Mastodawn

Ayon Nandi Jan 9, 2023

I'm OK with the fact that changes in neuroreceptor/neurotransmitter release dynamics could be v. small AND (probably?) with high variability across individual brains.

But, we have a good enough handle on the variability of these measurements?

Ayon Nandi Jan 9, 2023

This has bugged me, so curious what others think:

1) test-retest variability of dopamine release by raclopride PET reported to be (on the higher end) ~10~12% https://pubmed.ncbi.nlm.nih.gov/23238524/

2) D2/D3 binding measures (raclopride, fallypride) -- TRV also up to 10% or so in some reports
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7446562/

2) I've seen several papers reporting DA release and D2/D3 binding changes lower than these reported TRVs. **

*inc ones I've co-authored :(
#neuroimaging #PETimaging #neuroscience

Test-retest reproducibility of dopamine D2/3 receptor binding in human brain measured by PET with [11C]MNPA and [11C]raclopride - PubMed

In the present preliminary study, the test-retest reproducibility of BP of [C]MNPA and of [C]MNPA/[C]raclopride was reliable in the caudate and putamen.

PubMed

Ayon Nandi Dec 22, 2022

Show thread

bendfulcher Dec 22, 2022

@PessoaBrain Catie Chang's recent work is amazing on this.
e.g., https://www.sciencedirect.com/science/article/pii/S1053811921008636
e.g., https://link.springer.com/chapter/10.1007/978-3-030-59728-3_42

Ayon Nandi Dec 22, 2022

Luiz Pessoa Dec 21, 2022

Is there some work providing evidence that 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝗮𝗹 𝗰𝗼𝗻𝗻𝗲𝗰𝘁𝗶𝘃𝗶𝘁𝘆 𝗶𝗻 𝗳𝗠𝗥𝗜 is driven in part by non-specific and/or spurious signals?

Of course there's the entire "global mean regression" business that gets at this issue, but is there something separate from this debate that I can look at? Thanks.

By the way, is the fMRI community over here or still not?? Sigh.

#neurosciences
#fMRI

Ayon Nandi Dec 19, 2022

Luiz Pessoa Dec 18, 2022

Another 𝗱𝗼𝗽𝗮𝗺𝗶𝗻𝗲 𝗰𝗶𝗿𝗰𝘂𝗶𝘁 lurking there. This time involving the periaqueductal gray (PAG), bed nucleus of the stria terminalis, etc.

Work by the Kash lab: Chronic ethanol exposure modulates periaqueductal gray to extended amygdala dopamine circuit

https://www.jneurosci.org/content/early/2022/12/14/JNEUROSCI.1219-22.2022

#neuroscience

Chronic ethanol exposure modulates periaqueductal gray to extended amygdala dopamine circuit

The bed nucleus of the stria terminalis (BNST) is a component of the extended amygdala that regulates motivated behavior and affective states and plays an integral role in the development of alcohol-use disorder (AUD). The dorsal subdivision of the BNST receives dense dopaminergic input from the ventrolateral periaqueductal gray (vlPAG)/dorsal raphe (DR). To date, no studies have examined the effects of chronic alcohol on this circuit. Here, we used chronic intermittent ethanol exposure (CIE), a well-established rodent model of AUD, to functionally interrogate the vlPAG/DR-BNST dopamine circuit during acute withdrawal. We selectively targeted vlPAG/DRDA neurons in tyrosine hydroxylase-expressing transgenic adult male mice. Using ex vivo electrophysiology, we found hyperexcitability of vlPAG/DRDA neurons in CIE-treated mice. Further, using optogenetic approaches to target vlPAG/DRDA terminals in the dBNST, we revealed a CIE-mediated shift in the vlPAG/DR-driven excitatory-inhibitory ratio to a hyperexcitable state in dBNST. Additionally, to quantify the effect of CIE on endogenous DA signaling, we coupled optogenetics with fast-scan cyclic voltammetry to measure pathway-specific DA release in dBNST. CIE-treated mice had significantly reduced signal half-life, suggestive of faster clearance of DA signaling. CIE treatment also altered the ratio of vlPAG/DRDA-driven cellular inhibition and excitation of a subset of dBNST neurons. Overall, our findings suggest a dysregulation of vlPAG/DR to BNST dopamine circuit, which may contribute to pathophysiological phenotypes associated with AUD. SIGNIFICANCE STATEMENT: The dorsal bed nucleus of stria terminalis (dBNST) is highly implicated in the pathophysiology of alcohol use disorder and receives dopaminergic inputs from ventrolateral periaqueductal gray/dorsal raphe regions (vlPAG/DR). The present study highlights the plasticity within the vlPAG/DR to dBNST dopamine (DA) circuit during acute withdrawal from chronic ethanol exposure. More specifically, our data reveal that chronic ethanol strengthens vlPAG/DR-dBNST glutamatergic transmission while altering both DA transmission and dopamine-mediated cellular inhibition of dBNST neurons. The net result is a shift toward a hyperexcitable state in dBNST activity. Together, our findings suggest chronic ethanol may promote withdrawal-related plasticity by dysregulating the vlPAG/DR-dBNST DA circuit.

Journal of Neuroscience

Ayon Nandi Dec 19, 2022

Mark Rubin Nov 19, 2022

🆘 Some Mastodon Help! 🆘

🔹An easy-to-follow blog post to help get started on Mastodon, written by @djnavarro: https://blog.djnavarro.net/posts/2022-11-03_what-i-know-about-mastodon/

🔹An easy-to-use tool to automatically export the Mastodon handles of the people you follow on Twitter and import them to Mastodon, made by @Luca: https://fedifinder.glitch.me

🔹For psychologists, a list of psychologists on Mastodon, created by @kaitclark: https://kaitclark.github.io/mastodon-psychology/

#twitterMigration
#science
#psychology
#socialpsychology
#socialpsych
#socialscience

Everything I know about Mastodon – Notes from a data witch

A hastily written guide for data science folks trying to navigate the fediverse.

Notes from a data witch

Ayon Nandi Dec 15, 2022

Nicole Rust Dec 14, 2022

Let's celebrate the season with a bit of science! Starting a daily countdown of 10 modern and fascinating ideas about the brain for us all to discuss. How likely is this to be true? And if true, what are the implications?

Brain idea 10: Our moods may depend not just on what's happening in our brain, but also our gut. The gist of the idea is that the gut can send distress signals to the brain that can trigger fear and anxiety.

The friendly summary:
https://www.health.harvard.edu/diseases-and-conditions/the-gut-brain-connection

The deeper dive:
https://www.frontiersin.org/articles/10.3389/fgstr.2022.1019578/full

#neuroscience
(And despite my reluctance; because I'm trying to work out the hashtag habit here ...)
#BrainIdeasCountdown

The gut-brain connection - Harvard Health

The brain has a direct effect on the stomach, causing GI conditions. A person's stomach or intestinal distress can be the cause or the product of anxiety, stress, or depression....

Harvard Health

Ayon Nandi Dec 15, 2022

Nicole Rust Dec 15, 2022

Continuing the holiday celebration on Day 2 (of 10). Topic: Modern and fascinating ideas about the brain for us all to discuss. How likely is each idea to be true? And if true, what are the implications?

Brain idea 9: Across different individuals, the same brain functions are implemented by biological details that vary a lot. This is true even for simple circuits like the ones that control the stomach of a crab, where the numbers of ion channels can vary 2-6x across different crabs but the circuit always does the same thing.

The friendly version:
https://www.quantamagazine.org/eve-marder-on-the-crucial-resilience-of-neurons-20210517/

The deeper dive:
https://www.sciencedirect.com/science/article/pii/S0959438822001040

#neuroscience
(And because I'm trying to work out the hashtag habit here ...)
#BrainIdeasCountdown

Eve Marder on the Crucial Resilience of Neurons

Eve Marder’s research into the plasticity and resilience of nervous systems finds universal principles guiding life’s responses to stress.

Quanta Magazine

Ayon Nandi Nov 29, 2022

@AllenNeuroLab Nov 29, 2022

This isn’t the end for the amyloid treatment directions in Alzheimer’s disease. However there’s clearly lots of work left to do in fundamental/basic research in AD. I’m particularly a fan of diversifying our animal models based on a much larger diversity of mechanistic hypotheses of the causal pathways in the disease.

https://www.science.org/content/article/roche-alzheimer-s-antibody-fails-slow-cognitive-decline-major-test

Roche Alzheimer’s antibody fails to slow cognitive decline in major test

Results of phase 3 trials testing gantenerumab are latest blow to amyloid hypothesis

Ayon Nandi Nov 19, 2022

#introductions This is another attempt at starting a regular science and other stuff social media account from me, Ayon.

I work in #neuroimaging , focusing on imaging neuroreceptors at JHU. Also dabble in stats/data analysis and trying to make better, cooler brain images.

Been known to talk about science, sci-fi, pop culture, and other stuff I like.