RT Journal Article
SR Electronic
T1 Hippocampal and thalamic afferents form distinct synaptic microcircuits in the mouse frontal cortex
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.03.12.435140
DO 10.1101/2021.03.12.435140
A1 Kourtney Graham
A1 Nelson Spruston
A1 Erik B. Bloss
YR 2021
UL http://biorxiv.org/content/early/2021/03/13/2021.03.12.435140.abstract
AB Neural circuits within the frontal cortex support the flexible selection of goal-directed behaviors by integrating input from brain regions associated with sensory, emotional, episodic, and semantic memory functions. From a connectomics perspective, determining how these disparate afferent inputs target their synapses to specific cell types in the frontal cortex may prove crucial in understanding circuit-level information processing. Here, we used monosynaptic retrograde rabies mapping to examine the distribution of afferent neurons targeting four distinct classes of local inhibitory interneurons and four distinct classes of excitatory projection neurons in mouse infralimbic cortex. Interneurons expressing parvalbumin, somatostatin, or vasoactive intestinal peptide received a large proportion of inputs from hippocampal regions, while interneurons expressing neuron-derived neurotrophic factor received a large proportion of inputs from thalamic regions. A more moderate hippocampal-thalamic dichotomy was found among the inputs targeting excitatory neurons that project to the basolateral amygdala, lateral entorhinal cortex, nucleus reuniens of the thalamus, and the periaqueductal gray. Together, these results show a prominent bias among hippocampal and thalamic afferent systems in their targeting to genetically or anatomically defined sets of frontal cortical neurons. Moreover, they suggest the presence of two distinct local microcircuits that control how different inputs govern frontal cortical information processing.Competing Interest StatementThe authors have declared no competing interest.