Summary of journal club

Dopamine neurons response during reward-based learning reflects temporal shift of temporal difference model

Associative learning is very important for the animal survival and the dopaminergic neurons play an important role in this learning. They undergo an amplitude change from reward response to cue response as the trials progress. This dynamic is very similar to prediction error terms in animal learning models, the temporal difference (TD) algorithm. The feature of this algorithm is the gradual backward shift in the response from reward to cue. Previous studies could not detect the gradual backward shift in timing in dopamine responses. In the current study, the authors carried out classical conditioning experiments using fiber photometry and dopamine biosensors to try to examine this phenomenon. They were able to detect the backward shift in dopamine activity and these findings supports that TD learning can explain the dopamine neurons responses.

Study of a role of astrocyte Ca2+ in functional hyperemia in awake mouse model

A fundamental role of astrocyte Ca2+ is to amplify functional hyperemia when neuronal activation is prolonged.

A New Technique Based on Electrolyte Gel to Expand a Variety of 3D Staining Observation

The authors developed a highly optimized 3D staining imaging pipeline based on CUBIC and successfully stained and imaged whole adult mouse brains by using electrolyte gel to explore the optimal staining protocol.

Cell-type specificity of callosally evoked excitation and feedforward Inhibition in the prefrontal cortex

A research revealed the connectivity and intrinsic properties have profound impact on synaptic responses of pyramidal neurons.

Rapid eye movements and head direction cells recording reveal a possible cognitive procedure during REM sleep

Activity registration in the head direction system during rapid eye movement (REM) sleep revealed similar activation pattern as awake mice exploring the environment. Changes in the direction and amplitude of rapid eye movements during sleep correspond to changes in virtual head direction. Thus, these results show that cognitive procedures may occur while sleeping.

Spatial memory of rats was assessed by Barnes Maze test to determine whether long-term neuroinflammation in a rat model of cardiac arrest caused memory and cognitive impairment

Noninvasive in vivo quantification of neuroinflammation with relatively high sensitivity using positron emission tomography (PET) scans revealed significantly increased bilateral uptake of [18F]DAA1106 in the dorsal hippocampus for up to 180 days in rat models of cardiac arrest. Therefore, setting the Barnes maze test and then performing statistical analysis on the search time of rats for escape hole obtained that the long-term neuroinflammation after cardiac arrest, resulting in cognitive dysfunction.

A Approach to Quantify the Influence of Self-Grooming in Animal Social Behaviors

To explore the significance of self-grooming among animals in social behaviors, they develops a method to induce this behaviors and quantify the influence of self-grooming.

Thermal tolerance and susceptibility of the brain

The new research on inducing spreading depolarization in zebrafish’s nervous system under the hypoxia environment

TSPO is involved in the regulation of GSDMD-mediated inflammatory bowel disease and macrophage pyroptosis

Pyroptosis is a type of programmed cell death that usually occurs in inflammation. A new study reveals the molecular mechanism of mitochondrial protein TSPO in inflammation and pyroptosis, that is, TSPO expression is rapidly upregulated in response to inflammation, and TSPO interacts with pyroptosis effector GSDMD to provide cell protection and inhibit cell death.

Cell type-specific regulation of potassium channel modulating its excitability

Neuroinflammation underlie pathological brain in the diseases such as neurodegenerative disorders. A paper examined the effect of systemic inflammation on intrinsic properties of neuronal firing in prefrontal cortex and cerebellum. In vitro electrophysiology revealed a different directionality of the immune-triggered changes in small-conductance Ca2+-activated K+ channels (SK channels) for intrinsic excitability between prefrontal pyramidal neurons and cerebellar Purkinje cells.