Sound or Silence? The Pros and Cons of Cochlear Implants

Cochlear implants (CI) have been in use for several decades, yet there is still an active controversy surrounding these devices. While some people strongly advocate for the positive effect on an individual’s life, others claim that implants are dangerous both to individual health and to deaf culture at large [1].

PRO
Even though a CI cannot provide 100% hearing capability, it enables the individual to hear and understand most sounds. A cochlear implant does not amplify sounds like common external hearing aids, but stimulates the auditory nerve. The implant essentially replaces the function of the hair cells in the inner ear that usually register sound vibrations.  
Most importantly, a CI enables the individual to hear itself and thus learn to speak and articulate, and thus an implant helps to communicate with hearing people who do not know sign language. It also saves from  lip reading and generally depending on others for hearing help.
Another great advantage of having a CI for young people is that it can help them fully participate in mainstream schools and society, as well as broaden their career choices. While they may still be limited, the limitation won’t be as severe or as disabling as if they had no hearing choices available to them.
Being able to hear is also a measure of safety: the ability to locate sounds allows you to be more aware of perilous situations and hear impending danger such as a car coming from behind.

Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=29025007

CONTRA
CI require a surgical insertion and obviously surgery of itself always bears risks. Since the device has become available, risks have been minimized, however, complications may include occasional facial numbness or minor facial paralysis. Among individuals wearing a CI, there is also higher incidence of bacterial meningitis than for the general population. Thus an immunization is recommended. The body may also reject the implant, which could require removal or further surgery.
It is important to keep in mind that a CI doesn’t guarantee that a person will be able to hear and speak at a normal level. In some cases, the person with the implant can only hear some environmental sounds. Particularly for adults who receive the implant, electronic signals might not register fully and some hearing impairment may still occur. Also it is important to acknowledge that the auditory cortex is not used to process sound in the same way if a person has been deaf for a long time, so a CI wouldn't help much. 
Thus parents of hearing disabled children are urged  to make a decision as soon as possible for their child. Most people with an implant still need special help in learning to speak and in many cases they will still be stigmatized. Even though they can hear and speak, their hearing capabilities are not the same as a hearing person's [2]. Luckily, the devices are getting better and improved sound perception lets the wearer of CI integrate better into mainstream society.
Obviously, it takes time to get used to the implant and especially in the beginning, many need to get the CI reprogrammed according to their needs. Also, people with CI are limited on some physical activities, especially those involving contact with water, as this could damage the implant.

Controversy in Deaf Society
The primary controversy regarding CI concerns the definition of deafness as a disability. Recently journalist Enno Park gave a talk at the Berlin re:publica conference , where he spoke about his very personal view on the two (hearing and non-hearing) sides of society [3].
The medical community generally regards deafness as a disability that should be treated, and mainstream (hearing) society is of the opinion that hearing allows for a more fulfilling life. Meanwhile, many individuals who are deaf, as well as others who are familiar with non-hearing society feel that deafness is a cultural identity rather than a disability [4]. As a result, they feel that CI implies that there is something wrong with them that needs to be fixed, and that living as a person with a hearing impairment is inherently less fulfilling than as a "normal" person. Thus, these members of the community perceive putting something technical in their brains as serious affront.
Within the non-hearing community, there is a long history of disagreement: Some signing people feel that CI wearers are betraying their culture. Some even go as far as to describe implantation of children as “child abuse”. Also, with more people wearing CI, the need for sign-language interpreters decreases to the disadvantage of those who still rely on their services. On the other hand, parents that do not want their children implanted have to deal with hostility not only from the hearing community, but also from CI-wearers.




--> Get an idea how sound is perceived, through a CI! <--




Interestingly, the attitude towards sign language differs from country to country. In Germany and France, most people working in deaf education even don't speak sign language, and emphasis is placed on children learning to lip read [2,3]. In contrast, in the US, every police department should have one or more interpreters available on call [5]. It is likely that these attitudes and values will change over time, both with the rise of improving hearing technology and activism from within the deaf community.
The decision to receive a CI is a very personal one that should be considered with the help of a medical professional. Every parent with a hearing disabled child needs to decide for themselves what the best choice for their situation is.

Claudia Willmes
PhD Alumna, AG Eickholt / AG Schmitz

Background:
From 2007 to 2008 I worked at the Institute le Bruckhof in Strasbourg, France -  an institution for hearing disabled children, where many children wore cochlear implants [6]. They received special training in learning language and were encouraged to read lips instead of using sign language. However, I also took classes in an adult education center to learn DGS (German sign language) for one year and attended the university in Strasbourg to learn LSF (French sign language). Thus, I heard opinions from all sides: the hearing, the hearing disabled and signing, and those wearing CI.

[1] www.nad.org
[2] personal communication
[3] talk by Enno Park https://bit.ly/2K3MO8P
[4] Ohio University, The Institute for Applied & Professional Ethics https://bit.ly/2wxdrBg
[5] U.S. Department of Justice  https://www.ada.gov/q%26a_law.htm
[6] www.bruckhof.org/
 

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Retinal Implants

Science fiction movies or novels often pick cybernetic transformations of the human body as a "must-have" for the future. The idea of cybernatically-engineered eyes seems to be very popular.
 
Who would not appreciate a contact lens that connects to the internet and shows you all the information in real time like in the TV series Altered Carbon [1]? Nevertheless, some people have retinal implants or bionic eyes, because they cannot see without them. For example, individuals with neuronal degeneration of the retina have the possibility to get retinal implants to restore some of their vision. There are two diseases that cause the majority of retinal degeneration: retinitis pigmentosa (RP) and age related macular degeneration (ARMD).

Retinal Implants Can Restore Basic Greyscale Vision
RP is caused by mutations in more than 50 different genes, and thus can be inherited. Here, the translation of light to electrical signals by the rod photoreceptor cells is disrupted. The symptoms develop gradually, starting in most cases start with night blindness and loss of the peripheral vision. The symptoms affect both eyes equally. The disease progresses to affect the peripheral visual field and then the central area. Fortunately, only a few patients become completely blind [2].
In contrast to RP, in ARMD the central visual field is affected first. Macular degeneration mostly affects older people and does not lead to complete blindness. Nevertheless, loss of vision in the central visual field greatly affects the quality of life [3].
Fortunately, we live in the 21^st century, so our research on biomedical devices is already quite advanced. Now, patients have the possibility to get retinal implants. These implants mostly work with glasses and a build-in external camera. The camera sends the information to a mini computer. Here the information is processed and send to a retinal implant via cable (see figure). The implant electrically stimulates the nerve fibres similarly to functioning photoreceptors. The current implants are able to restore basic greyscale light perception, so that patients are even able to identify objects [4].

Source: https://bit.ly/2I7HRyk

The Bionic Eye
Argus II, also known as the "Bionic Eye", is the oldest model with an external camera. It has been approved for clinical application in Europe and the US. This device helps patients see patterns of light, which they learn to interpret in time [5].
Similar to the Argus II is the Boston Retinal Implant. The only difference is the amount of electrodes in the retinal implant. The Boston Retinal Implant has a higher resolution due to higher number of electrodes. This model is still being tested in animals and not yet in clinical studies [6].
The Intelligent Medical Implant (IMI) is also comparable to the Argus II. The difference and advantage to the Argus II is that the IMI can be individually calibrated upon implantation. This allows adjustment of visual perception for each patient. The IMI is not available for clinical applications yet, but is in clinical trial in Europe [7].
One disadvantage of all three models are the transscleral cables that connect the outside electronics with the retinal implant. Here, the risk of infections due to long term implantation is higher as for example with a different model, the Epi-Ret 3. This model is also a combination of an external camera and a retinal implant, but there is no external case or transscleral cables. The information is send wirelessly to the retinal implant, where it is translated to electrical stimulation. This is an advantage due to the missing transscleral cables, eliminating problems like infections or other postoperative complications. Epi-ret 3 is currently in clinical trials in Europe [8].

Getting Closer to Natural Vision
A very different model to the ones mentioned so far is the Alpha-IMS. The Alpha-IMS works without external cameras but instead has a retinal implant that consists of a 1500-pixel multiphotodiode array mimicing thereby very closely the natural vision. The light sensitive photodiode responds to light and sends a signal to a subdermal power control. This power control can be charged wirelessly by a handheld device that also adjusts the light sensitivity [9]. The model is currently under clinical trial in Europe and Hong Kong. Unfortunately, there have been cases with corrosion of the implant and subretinal bleeding [10, 11].
In 2014 a review analysed these devices and looked at the visual performance in patients [4]. They showed that the Alpha-IMS and Argus II have the best results, when it comes to visual performance. The best recorded visual acuity to date is 20/1260 of the Argus II [12]. Compared to perfect 20/20 vision, patients remain nearly blind, but they are able to see significantly more than without the implants.
The Alpha-IMS may have a better resolution in a smaller more focused central vision, but the Argus II has a bigger field of view. Similar to the Argus II, the Boston Retinal Implant has an array with more electrodes, and in theory this would give a higher resolution. However, there is still no data to back this up. In addition, these larger devices might create more heat.
In conclusion, there are good options for people with retinal degeneration. Though the presented retinal implants still have limited resolution and biocompatibility, future research will help improving these features. Unfortunately, for the privileged people with intact vision, retinal implants with a wifi connection (still) remain science fiction.

Larissa Kraus
PhD Student, AG Holtkamp


[1] Altered Carbon, Netflix, 2018
[2] https://bit.ly/2r9gZ5C
[3] https://bit.ly/1dBK8yC   
[4] Chuang et al., Br. J. Ophthalmol, 2014

[5] https://bit.ly/1PwBZGY
[6] Rizzo, J. Neuro-Ophthalmology, 2011
[7] Keserü et al., Acta Ophthalmol, 2012
[8] Klauke et al., Investig. Opthalmology Vis, 2011
[9] Kusnyerik et al., Investig. Opthalmology Vis 2012
[10] Stingl et al., Proc. R. Soc. B Biol. Sci., 2013
[11] Zrenner, Sci. Transl. Med., 2013
[12] Humayun  et al., Ophthalmology, 2012

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Futuristic Brain Implants: Review of the Series "Black Mirror"

Black Mirror is a  British Sci-Fi series created by Charlie Booker which explores diverse day-to-day topics from our obsession with social media (Nosedive, Series 3 Episode 1) to things which we can't even imagine, like placing a person's consciousness in a physical object (Black Museum, Series 4  Episode 6)! They often delve into neuroscience in the not-so-distant future, in particular, the ways in which different sorts of technology change the way that we think and behave.
 

Spoilers ahead!

The episode The Entire History of You (Series 1 Episode 3) is set in an alternate reality where people can have a 'grain' implanted to record every moment of their lives and replay memories on a screen whenever they want. However, replaying memories becomes a nightmare, such as for a man who finds out about his wife's affair! Perhaps forgetting is blessing in disguise! I found the episode Crocodile (Series 4 Episode 3) thrilling, and I am sure this will keep you at the edge of your seat! The main character witnesses a road accident and is interviewed by the insurance company as a witness. During the witness interrogation, the investigator uses a memory recaller device to look at the recent memories of her interview partner. As the main character had previously committed a crime, she fears it will be revealed when the recaller scans her memories, so she starts a string of murders to cover up her crime. The best part is the climax-  with the police turning to a pet guinea pig as witness!

 Welcome to neuroscience in the not-so-distant future

The series has made me thinking about aspects of neuroscience, and there are still many unanswered questions. Could the guinea pig or other animals have better memory recall or intelligence than us, human beings? Or could a memory recall device be feasible in the near future? (It would be great to have, especially to quote papers during lab meetings that you have read and forgotten!) Of course, this would necessitate that we first understand how memory is encoded or replayed. Having consciousness transferred to a physical object poses also the big question: Where is consciousness located in the first place? The reality is that we are far from understanding these problems. This is why we have an exciting time ahead of us to learn more about the brain and invent futuristic devices. For those who have not seen Black Mirror, I would definitely recommend it.

Aarti Swaminathan
PhD Student, AG Schmitz





This article originally appeared June 2018 in CNS Volume 11, Issue 2, Brain Invasion

A Day in the Life of Gondi, the Little Toxoplasm

Hey there fellow organism! Yeah, I'm talking to you, bighead. Just because I am only a few micrometers long, doesn't mean you get to ignore me.

Look, I happen to be stuck – in you.
And it's really all your fault. You must have gotten yourself infected by eating uncooked meat or, if you happen to have a cat you probably got a little too close to its feces – either way, you're gross. Do you remember that flu you had a few weeks ago? That was me. Or rather that was your immune system trying to get rid of me, which by the way – rude! Others of my family have infected about half of your sorry population around the globe and most of them were doing fine, no symptoms whatsoever. The way a host should behave, if I may say so. So now, I am crammed into a cyst with who knows how many of my kind and have to lie around semidormant. I don't know if I will ever see the comfy squishy cells of a cat's intestine again, ergo I don't know if I will ever get to sexually reproduce again. Picture that! Sure, I could keep on merrily dividing in you but then your immune system would probably start going all rampage-y again on me, so no thanks. You are just seriously lacking as an intermediary host.

Dividing T. gondii, courtesy of Ke Hu and John M. Murray [1]

 
And this is not me whining – I happen to have been through a whole lot of intermediary hosts: mice, rats, once even a cow. I might be a small, arched parasite but I am capable of surviving in just about any warm-blooded animal. And outside of them, too! In fact, I have been told that I am very resilient to cold climates, thank you very much. Plus, in mice and rats I stand at least a fighting chance to get back into a cat. See, I happen to not only be resilient, highly international and wisely adjusting my proliferation rate so that hosts don't kick me out – I can tweak behaviour of animals who are ten thousand times my size. See, I propagate into my inter-host's brain, I fiddle about a little here and a little there, some hypomethylation of genes that are expressed in the amygdala, a bit of histone-lysine acetylation of astrocytes. And voilà: mice lose their fear of cat urine. Rats even find the smell more attractive! They stop avoiding marked territory and they become altogether less capable of escaping the cat they sniffed out. Isn't that just great?
But humans...pesky. There was a time when getting you eaten by a big cat, say a lion, was a real option. But nowadays you have become so cuddled away and safe with your sweet little overfed furballs. I mean, toxoplasma gondii is no quitter, mark my words! A toxoplasma infection is associated with some neat little behavioural changes in humans: Males show higher levels of testosterone, are more likely to disregard rules. Both of your sexes perform worse in respect to reaction time and concentration. We are associated with higher risks for schizophrenia, bipolar disorder, suicide and traffic accidents.
Still, getting out of a human and back into a cat is hard work. I'm a nice little fella, just wanting to get back to my favourite host.

So. About my being stuck – would you care to get eaten by your cat?

Malika Renz
MSc Student, MedNeuro

Want to know more?
[1]  Hu et al., PLoS pathog 2006
[2] Webster, Schizophrenia bull, 2007
[3] Flegr, Schizophrenia bull, 2007.
[4] Torrey et al., Schizophr res, 2012 
[5]  Hurley et al., J neuropsy clin neurosci, 2012 


This  article won the Best Contribution award for the  issue Brain Invasion  Thanks Malika for such a fun take on a complicated subject!

Like what you see? Interested in contributing? We are always looking for new authors and submission on anything related to the topic of neuroscience. Send us an article, some beautiful shots from your microscope, poems, short stories, critiques, reviews- anything to cns-newsletter@charite.de! 

New Issue Out Now: BRAIN INVASION

The brain is an amazing thing: it allows to think, feel, create and do lots of other less-glamorous things like breathe and digest your lunch. But what's even more amazing is the system that our body has involved to keep it that way. This issue of the newsletter is all about how things can find their way inside our heads- for better or for worse!

 

https://bit.ly/2LwCVRU

First off, have a look at our primer on the different ways in, intracortical implants to poorly cooked food (page 3), and learn more about the body's first line of defense (page 7-8). We also have a first-hand account of a particularly sneaky invader (page 4), as well as clinical reports of foreign objects turning up where they definitely shouldn't be (page 9)! But it's not all bad news! Recent developments have meant that our senses can be augmented (or even repaired, pages 5 and 10), and optogenetics has "illuminated" a whole new realm of experimental possibilities (page 13-14). Are we ready for blending our brains and technology? We have two stories examining the ways authors play with the idea of cyborgs (pages 11-12), as well as providing some thought-provoking watching material (page 7).
Of course, we also have stories from the here and now on campus. What's the point of publishing negative results (page 19)? Are MSc students treated fairly (page 18)? What is it like to work for a big pharma company (page 16)? And, most importantly: what the heck is going on with those yellow buses all over campus (page 21)?

Happy reading, dear readers! We hope that this issue will stick in your head.

Constance Holman and Claudia Willmes
Editors-in-Chief

Neuroscience Podcasts to Seriously Send Those Brain Cells Firing

There’s only so much time one can dedicate to surfing Netflix, listening to Spotify or watching reality TV. At some point, you are adamantly looking for intellectual forms of entertainment. Enter podcasts- the audible version of blogs.

Those with a story-telling flair can keep one indulged for hours. Others that present educational or scientific content keep you intellectually engaged and listening to them are by no means a passive activity. If the podcast’s host has a dulcet tone and knows how to keep things moving, even stuff that you probably couldn’t care less about will become potentially interesting. Which brings us to the million dollar question- with a plethora of science podcasts available, which ones should you listen to? More specifically, are there podcasts that deal with Neuroscientific topics? This was the quest I took two months ago.  Below are some of the Neuroscience podcasts, in no particular order, which might be the answer to your curiosity or intellectual thirst.

1. You are not so smart

Image courtesy: David McRaney, https://bit.ly/2yckkno

Host: David McRaney
Average length: 50-60 min.
How active? : very. uploads content every month, sometimes even twice a month.
The good: Compares different psychology/neurosci topics relevant to current topics and affairs in everyday world. His podcast episodes always leave you feeling sober or humbled by the fact that how subjective, unpredictable and sometimes fickle our human selves can be. Except for a few mins of ads in the beginning and centre, there are no distractions. He also has an excellent way of introducing his guests in that he first gives an overview of the topic and then lets his guest take centre stage. He also doesn’t ramble or try to chime in with his own opinions during the interviews. Plus his voice is deep and lucid which makes it easier to continue listening to him for extended periods of time.
Start where: Tribal Psychology; Selfie; The Dunning-Kruger effect (but really too many good episodes here)
What’s missing? The podcast is overall excellent and you are seriously missing out if you have not heard of YANSS before. Perhaps the only thing you might find lacking would be that this is not, strictly speaking, a Neuroscience specific podcast but borders around Psychology, Pop culture, Neuroscience and Behaviour [1].


2. Brain Science Podcast

Image courtesy: Virginia Campbell, https://bit.ly/1BtSxxs

Host: Ginger Campbell, M.D
Average length: 60 min
How active? : very. technical and less technical content uploaded regularly since 2008
The good: This one is for hard-core Neuroscience enthusiasts. If you are a grad student and are looking for something other than the oft-repeated topics such as reproducibility crisis, women/diversity in STEM than this IS the place for you. There are 100+ episodes available as Dr. Campbell’s podcast has been one of the longest running Neuroscience podcasts to date. She discusses really thought-provoking books that are related to different subdivisions of Neuroscience and has interviewed many leading experts in the field including Drs. Michael Gazzaniga, Christof Koch, Temple Grandin and György Buzsáki to name a few. Listening to Dr. Campbell is like having your extremely well-educated grandma let you in on the intellectual discussions she has with all of her guests.
Start where: Counting Neurons with Dr. Suzana Herculano-Houzel ; John Medina on Aging Well
What’s missing? Some of the older episodes require premium subscription (but full access is possible at 5 bucks a month) so listening to Dr. Koch or Dr. Gazzaniga comes at a small cost. However, you can listen to the more recent episodes uploaded after 2013 for free. All podcasts come with transcripts as well as links to discussed books and papers. Beware though as some of the links may not work due to website revamping [2].

3. Shrink Rap Radio

Image courtesy: David Van Nuys, https://bit.ly/2IxwBMF

Host: David Van Nuys, Ph.D
Average length: 60 min
How active? : very. There are almost 3-4 episodes posted every month.
The good: Dr. Van Nuys also has a talent of making his guests feel at ease and asks thought-provoking questions. There’s also a decent amount of content related to mind-body-soul science if you are into that stuff. Together with the Brain Science Podcast, this is one of the oldest running podcast I could find with quality content.
Start where: Quieting your inner critic and rising above social anxiety with Ellen Hendriksen; The Body of Sex with Sarah Byrden ; The Silent Epidemic of REM Sleep Loss with Rubin Naiman
What’s missing? This is more of a Psychology podcast but has close overlap with Cognitive Neuroscience because of the topics covered. Some episodes are longer than 60 mins so reserve this one for weekends [3].

  4.  A Neuroscientist Explains

Image courtesy: Max Sanderson, https://bit.ly/2Ilyx6M

Host: Daniel Glaser, Ph.D
Average length: 30-40 mins
How active? : Intermittent. Has two seasons out (1^st season: 8 episodes, 2^nd season: 7 episodes); one in 2017 and the other in 2018.
The good: This one’s for all the British accent lovers. The episodes have a very soothing background music so that it literally calmed my anxiety during stressful morning commutes. Quite accessible, user-friendly and the topics are quite relevant if you are interested in Neurosci but don’t know where to start
Start where: A Neuroscientist explains: how music affects the brain; A Neuroscientist Explains: is the internet addictive? ; A neuroscientist explains: how the brain stores memories
What’s missing? The podcast is not very active so if you are looking for interviews and bringing yourself up-to-date with current trends, this isn’t the one [4].

  5. Smart drug smarts

Host: Jesse Lawler (permission pending)

Average length: 40-60 min
How active? : very. Content updated religiously
The good: This podcast has one of the most amusing introduction out of all science podcasts. The episodes are quite fast paced so if you cannot stand slow discussions, go for this one. Lawler is a self-proclaimed science fan boy and is an excellent host. The voice quality is excellent and all the podcast episodes come with detailed transcripts as well as summary notes. The website overall is very decently designed which makes spending time here more fun.
Start where:     Brain Implants – Medical and Beyond with Dr. Brett Wingeier; Head in the Game with Dr. John Sullivan; Cognitive Fallacies with Dr. Richard E. Nisbett ; What are “Fast-Spiking Interneurons”?; Placebo: the Power of the Mind to Heal
What’s missing? Lawler is quite enthusiastic and throws in a lot of slangs and casual phrases so those looking for more serious style discussions may not agree with his hosting style (not that I’m complaining) [5].

  6.  Neurotransmissions

Image courtesy: Joe Schumacher, https://bit.ly/2KJQjlh

Host: Ben Scholl, Ph.D., Joe Schumacher, Ph.D., and Misha Smirnov, Ph.D.
Average length: 30-40 mins
How active? : post content every other month. Haven’t been very active for the last 2 months though.
The good: started by post-docs at Max Planck, Florida, this podcast discusses latest topics in Neuroscience in an almost jargon-free manner. Quite accessible for the general audience in terms of content. Voice quality decent and all of the hosts are quite adept at making things moving and not chiming in too often. The general mood of the podcast is academic style and formal. Go for it if you are into interviews or seeking some inspiration.
Start where: Science writing and life living with Dr. Brett Mensh; Sunposium 2017: Part 2, Technological innovation with Drs. Ed Boyden & Viviana Gradinaru; Live from Sunposium 2017: Part 1, The Value of Scientific Knowledge with Dr. Thomas Südhof
What’s missing? Could be a bit dry at times. Needs some light-hearted humor [6].

7. Neuroscientists Talk Shop

Image courtesy: Neuroscientists Talk Shop, https://bit.ly/2IDc5cJ

Host: various including Salma Quraishi,Ph.D, Alfonso Apicella,Ph.D, Charles Wilson,Ph.D (and others)
Average length: 40 min
How active? : usually post 2-3 episodes every month but have not been very active recently.
The good: started by a group of professors and graduate students at UT San Antonio, this podcast is more hinging on the technical side. Guest scientists are invited in each episode and talk about their research. The questions are more symposium-style and the atmosphere is quite academic and scholarly. If you are looking for some inspiration on someone who is working on a similar topic to yours, maybe look here for some inspiration. Although the podcast has many moderators, the questions never get jumbled up so that everything is easy to follow. Also the podcast has no ads which means no distractions.
Start where: (Interview with) Rusty Gage, PhD ; Ann Graybiel PhD ; Dwight Bergles PhD
What’s missing? Sometimes voice quality not as crisp as you’d like it to be. Could be a bit dry and information-heavy as the time duration is only 40 mins [7].

8. Honourable mentions:
These include Neuroscience podcasts that are no longer active. Neuropod (Nature podcasts on Neuroscience) which ran till late 2015 [8]. The Naked Scientists (Naked Neuroscience) which stopped updating after 2014 [9]. Note that the Naked Scientists podcast on other science disciplines such as Genetics, Astronomy and so on are still regularly updated.

Image courtesy: Chris Smith, https://bit.ly/2IDMkcw

Word to the wise: avoiding mindless media consumption does not mean that your ears have to be glued to scientific podcasts. Cut your poor brain cells some slack and have some time off to digest all the information.

Did we miss any cool podcasts that talk about science and especially all-things-brain? Give us a shout out at cns-newsletter@charite.de about any potential hidden gems that you know.

by Zara Khan, MSc Student MedNeuro

[1] https://bit.ly/2yckkno
[2] https://bit.ly/2jYSpCi
[3] https://bit.ly/2rGYGpK
[4] https://bit.ly/2Ilyx6M
[5] https://bit.ly/2rM38Ui
[6] https://bit.ly/2rNOSuf
[7] https://bit.ly/2IDc5cJ
[8] https://go.nature.com/2rJtyG9
[9] https://bit.ly/2IDMkc

Drug-induced mental disorders: a common reason for concern?

Most psychoactive drugs alter our cognitive and emotional states, but does chronic use implicate a pathological change in our mental condition?

If we chronically alter transmitter pathways, adaptations will certainly take place. Adaptations are expressed during addiction in sensitization and desensitization of transmitter pathways. This leads to an up- or downregulation of receptors and transporters and eventually to tolerance as well as craving when the drug is withdrawn. These adaptations originate out of natural compensation, but leave former drug users with an imbalanced brain chemistry and an increased risk for several mental disorders. Patients with substance disorders are twice as likely to suffer from mood and anxiety disorders (National Institute on Drug Abuse). Basically, all drugs alter dopaminergic regulation and consequently, our motivation and ability to experience pleasure is changed. Several drugs also cause neurotoxicity and can therefore easily lead to permanent damage, e.g. depression after prolonged ecstasy use due to serotonergic cell death. 
Apart from emotional disturbances, the most common drug-induced illness is psychosis; with alcohol (18%), cannabis (13%) and cocaine (18%) being the most common inducers [1]. One could blame everything on 'high risk drugs', yet, for many mental disorders susceptibility genes have been found, e.g. the VAL/VAL variant of the COMT-gene in cannabis users who go on to develop schizophrenia [2]. Other factors, such as food intake, can severely affect mental outcome after chronic drug use, for example vitamin b12 deficiency in alcoholics, which can lead to several mental disorders, including psychosis and depression.
Hence, aside from chronic substance use, our environmental and genetic conditions play a decisive role in the development of long lasting drug-induced mental pathologies.
  
[1] Drake et al., Am J Psychiatry, 2011
[2] Caspi et al., Biol Psychiatry, 2005

By Anne Schwerk, PhD Alumna, AG Neuronal Regeneration and Plasticity (Dr. med. Barbara Steiner)


This article originally appeared in CNS Volume 5, Issue 1, Mental Health Disorders