Theta-gamma coupling as « Eureka »?

Spatial reference memory in rodents represents a unique opportunity to study brain mechanisms responsible for encoding, storage and retrieval of a memory. Even though its reliance on hippocampal networks has long been established, the precise computations performed by different hippocampal subfields during spatial learning are still not clear. In our Cerebral Cortex paper, to studyLire la suite « Theta-gamma coupling as « Eureka »? »

Beyond the frontiers of neural types (and monkey vocalizations !?!)

Beyond the frontiers of neuronal types Cortical neurons and, particularly, inhibitory interneurons display a large diversity of morphological, synaptic, electrophysiological, and molecular properties, as well as diverse embryonic origins. However, a broad variability is generally observed even among cells that are grouped into a same class. In our Frontiers in Neural Circuits article in collaborationLire la suite « Beyond the frontiers of neural types (and monkey vocalizations !?!) »

Sampling the « dynome » leads to dynamic Functional Connectivity

Simulations of whole-brain mean-field computational models with realistic connectivity determined by tractography studies enable us to reproduce with accuracy aspects of average Functional Connectivity (FC) in the resting state. Most computational studies, however, did not address the prominent non-stationarity in resting state FC. In our NeuroImage paper, we show that this non-stationarity reveals a richLire la suite « Sampling the « dynome » leads to dynamic Functional Connectivity »

Broad-band gamma from highly synchronous activity?

Visual stimulation elicits neuronal responses in visual cortex. When the contrast of the used stimuli increases, the power of this induced activity is boosted over a broad frequency range (30–100 Hz), called the ‘‘gamma band.’’ However, previous models trying to explain contrast-related power enhancements using synchronous oscillations failed to reproduce the observed spectra because theyLire la suite « Broad-band gamma from highly synchronous activity? »

Hippocampal theta without pacemakers

Hippocampal theta rhythm is crucial for spatial memory and is thought to be generated by extrinsic inputs. In our Nature Neuroscience paper, though, we show that, using a complete rat hippocampus in vitro, several intrinsic, atropine-resistant theta generators can be found directly in CA1. These oscillators were organized along the septotemporal axis and arose independentlyLire la suite « Hippocampal theta without pacemakers »