Topic: neural ensembles

Neurons in the cortico-basal ganglia circuit become excessively synchronised at beta frequencies (15-35 Hz) in Parkinson’s disease. However, it is unclear how this synchronised firing evolves across the network. Beta synchrony has often been assumed to emerge homogenously across the neurons within anatomical structures of the basal ganglia. However, it is possible that beta oscillations may emerge in a modular fashion within the neurons that make up an anatomical structure. We hypothesized that neurons in subregions of the basal ganglia preferentially reflect onset and offset of beta oscillati

Executing memory-guided behavior requires storage of information about experience and later recall of that information to inform choices. Awake hippocampal replay, when hippocampal neural ensembles briefly reactivate a representation related to prior experience, has been proposed to critically contribute to these memory-related processes. However, it remains unclear whether awake replay contributes to memory function by promoting the storage of past experiences, facilitating planning based on evaluation of those experiences, or both. We designed a dynamic spatial task that promotes replay befo

Information in the nervous system is encoded by the spiking patterns of large populations of neurons. The analysis of such high-dimensional data is typically restricted to simple, arbitrarily defined features like spike rates, which discards information in the temporal structure of spike trains. Here, we use a recently developed method called SpikeShip based on optimal transport theory, which captures information from all the relative spike-timing relations among neurons. We compared spike-rate and spike-timing codes in neural ensembles from six visual areas during natural video presentations.

Reinstating details of previously seen stimuli given a recall cue is a common cognitive function. Studies suggest that such recollection involves hippocampus-mediated top-down reactivation of neural ensembles active during encoding, yet the neural mechanisms of such generative retrieval remain unknown. We formulate a biologically plausible hypothesis where transient cholinergic modulation, known to enhance backpropagated action potentials and trigger recall, initiates backward signals from sparse neurons discriminatively representing the cue to cortical areas encoding the trace. These signals

The coordinated recruitment of neural ensembles is thought to underlie behaviourally relevant information processing in the brain. These ensembles are temporally dynamic with individual neurons flexibly recruited into functional groups. In premotor cortex, intermingled neurons are activated during movement planning and execution but also in response to contextual cues, and reward. However, probing the behavioural role of these ensembles and understanding the circuit mechanisms underlying dynamic ensemble formation has been challenging due to the difficulty of flexibly manipulating individual c