S100A8-enriched microglia populate the brain of tau-seeded and accelerated aging mice.

Long considered to fluctuate between pro- and anti-inflammatory states, it has now become evident that microglia occupy a variegated phenotypic landscape with relevance to aging and neurodegeneration. However, whether specific microglial subsets converge in or contribute to both processes that eventually affect brain function is less clear. To investigate this, we analyzed microglial heterogeneity in a tauopathy mouse model (K18-seeded P301L) and an accelerated aging model (Senescence-Accelerated Mouse-Prone 8, SAMP8) using cellular indexing of transcriptomes and epitopes by sequencing.

Mechanisms underlying desynchronization of cholinergic-evoked thalamic network activity.

Synchronous neuronal activity in the thalamocortical system is critical for a number of behaviorally relevant computations, but hypersynchrony can limit information coding and lead to epileptiform responses. In the somatosensory thalamus, afferent inputs are transformed by networks of reciprocally connected thalamocortical neurons in the ventrobasal nucleus (VB) and GABAergic neurons in the thalamic reticular nucleus (TRN). These networks can generate oscillatory activity, and studies in vivo and in vitro have suggested that thalamic oscillations are often accompanied by synchronous neuronal activity, in part mediated by widespread divergence and convergence of both reticulothalamic and thalamoreticular pathways, as well as by electrical synapses interconnecting TRN neurons.

Impact of cortical plasticity on patterns of suprathreshold activity in the cerebral cortex.

There are many cellular and synaptic mechanisms of plasticity in the vertebrate cortex. How the patterns of suprathreshold spiking activity in a population of neurons change because of this plasticity, however, has hardly been subjected to experimental studies. Here, we measured how evoked patterns of suprathreshold spiking activity in a cortical network were modified by cortical plasticity with single-cell and single-spike resolution.

Impact of cortical plasticity on information signaled by populations of neurons in the cerebral cortex.

The performance of neural codes to represent attributes of sensory signals has been evaluated in the vertebrate peripheral and central nervous system. Here, we determine how information signaled by populations of neurons is modified by plasticity. Suprathreshold neuronal responses from a large number of neurons were recorded in the juvenile mouse barrel cortex using dithered random-access scanning.