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The neural mechanism responsible for context inference remains unknown. Here, the authors show that a PFC-MD neural network with a Hebbian plasticity rule achieves rapid online context inference and alleviates catastrophic forgetting.

The computational mechanism by which the mediodorsal (MD) thalamus enhances prefrontal activity to enable cognitive flexibility in context-dependent decision making is not fully understood. Here authors build a computational model incorporating genetically identified thalamocortical connectivity and interneuron cell types. Together with experimental testing, authors show that addition of a feedforward MD thalamus to the recurrent prefrontal cortex circuit increases robustness to low cueing signal-to-noise ratio, enhances working memory, and enables rapid context switching.

The authors trained mice to attend to or suppress vision based on behavioral context and show, through novel and established techniques, that changes in visual gain rely on tunable feedforward inhibition of visual thalamus via innervating thalamic reticular neurons; these findings introduce a subcortical model of attention in which modality-specific thalamic reticular subnetworks mediate top-down and context-dependent control of sensory selection.

By examining neural responses from tree shrews performing hierarchical decision tasks with rule reversals, the authors identify a thalamocortical mechanism for regulating cognitive flexibility.

The mediodorsal nucleus of the thalamus amplifies the functional connectivity of the prefrontal cortex, thereby sustaining cortical representations of rule sets without relaying categorical information.

While the relationship between motivation and sleep is intuitive, its behavioral and neural features are poorly understood. A new study tackles both issues, showing that dopaminergic neurons in the ventral tegmental area mediate this relationship.

Using optogenetics and multi-electrode recording in behaving mice, the authors find that briefly driving the thalamic reticular nucleus (TRN) switches thalamocortical firing mode and generates neocortical spindles, which have been implicated in memory and disease. These findings provide causal support for the idea that the TRN is involved in state regulation and introduce a new model for addressing the role of spindles in behavior.

Rikhye et al. recorded prefrontal and thalamic populations from mice performing attention selection across different contexts. By encoding context, the thalamus both enhances and suppresses prefrontal representations in a context-appropriate manner.

Two different cell types in the mediodorsal thalamus have complementary roles in decision-making, with one type of mediodorsal projection amplifying prefrontal activity under low signal levels and one type suppressing it under high noise levels.

IL-17a induced by immune activation affects cortical neural activity and promotes social interaction in a mouse model of neurodevelopmental disorders.

Increased activity of dopamine receptor type-2 (D2R)-expressing cells in the nucleus accumbens of rats during a ‘decision’ period reflects a ‘loss’ outcome of the previous decision, and predicts a subsequent safe choice; by artificially increasing the activity of D2R neurons during the decision period, risk-seeking rats could be converted to risk-avoiding rats.

An innovative approach has been used to link genetics to behaviour in mice. The analysis reveals that the gene Gpr12 underpins the role of the brain’s thalamus region in maintaining short-term memory.

A study integrating single-cell RNA-sequencing and electrophysiology data shows that in mouse, the cellular repertoire of the thalamic reticular nucleus is characterized by a transcriptomic gradient defined at its extremes by mutually exclusive expression of Spp1 and Ecel1, providing insights into the organizational principles underlying the divergent functions of this brain region.

The locus coeruleus is known to be an essential source of neuromodulation that influences sensory processing, including the enhancement of feature selectivity associated with attentional focus. A new study shows that the primary sensory thalamus encompasses one circuit that underlies this enhancement.

Roy, Zhang et al. discuss how modern neuroscience is revealing underappreciated heterogeneity in thalamic cell types, which leads to the idea that ‘thalamic subnetworks’ provide a more appropriate level of functional description than thalamic nuclei.

Identification of sleep-active and sleep-promoting neurons in the preoptic area of the hypothalamus using neural projection tracing tools to target this population among a group of intermingled neurons, all with various functions.

The authors propose a new framework for the thalamus in cognition. They review findings from rodents and primates, emphasizing thalamic control of functional cortical connectivity, its putative mechanisms and role in flexible construction of task-relevant cortical networks.