Hippocampal hyperactivity in a rat model of Alzheimer's disease.

Neuronal network dysfunction is a hallmark of Alzheimer's disease (AD). However, the underlying pathomechanisms remain unknown. We analyzed the hippocampal micronetwork in transgenic McGill-R-Thy1-APP rats (APPtg) at the beginning of extracellular amyloid beta (Aβ) deposition.

Temporally precise control of single-neuron spiking by juxtacellular nanostimulation.

Temporal patterns of action potentials influence a variety of activity-dependent intra- and intercellular processes and play an important role in theories of neural coding. Elucidating the mechanisms underlying these phenomena requires imposing spike trains with precisely defined patterns, but this has been challenging due to the limitations of existing stimulation techniques. Here we present a new nanostimulation method providing control over the action potential output of individual cortical neurons.

Dysfunction of Somatostatin-Positive Interneurons Associated with Memory Deficits in an Alzheimer's Disease Model.

Alzheimer's disease (AD) is characterized by cognitive decline and neuronal network dysfunction, but the underlying mechanisms remain unknown. In the hippocampus, microcircuit activity during learning and memory processes is tightly controlled by O-LM interneurons. Here, we investigated the effect of beta-amyloidosis on O-LM interneuron structural and functional connectivity, combining two-photon in vivo imaging of synaptic morphology, awake Ca imaging, and retrograde mono-transsynaptic rabies tracing.

Intracellular responses to frequency modulated tones in the dorsal cortex of the mouse inferior colliculus.

Frequency modulations occur in many natural sounds, including vocalizations. The neuronal response to frequency modulated (FM) stimuli has been studied extensively in different brain areas, with an emphasis on the auditory cortex and the central nucleus of the inferior colliculus. Here, we measured the responses to FM sweeps in whole-cell recordings from neurons in the dorsal cortex of the mouse inferior colliculus.

Large GABAergic neurons form a distinct subclass within the mouse dorsal cortex of the inferior colliculus with respect to intrinsic properties, synaptic inputs, sound responses, and projections.

Neurons in the inferior colliculus (IC) show a remarkable diversity in their responses to sound, but it has been difficult to relate these responses to their morphology. Large cells, which are found in all subdivisions of the IC, may form an exception. We found that large neurons of the mouse dorsal cortex of the IC were GABAergic and were contacted by vesicular glutamate transporter 2-containing somatic terminals, as previously observed for the rat IC.