Topic: layer 5 pyramidal neurons

Layer 5 pyramidal neurons (L5 PNs) are a major cortical output. Their connectivity approximates a recurrent neural network (RNN), with the majority of inputs coming from other L5 PNs. These neurons may underlie anesthesia-induced unconsciousness, by restricting information output from cortex. Therefore, understanding the formation of the L5 PN circuitry, from the time at which L5 PNs first enter cortex, would provide insight into how a biological RNN can be constructed. However, this is technically challenging because, in mice, L5 PNs first enter cortex at embryonic day (E) 13.5, five days bef

Understanding the circuit mechanisms underlying the loss of consciousness during general anesthesia is a long-standing question. Activity within cortex drives conscious perception and, hence, the loss of consciousness is thought to result from the disconnection of cortex from subcortex. Here, we identify a change in the correlation structure of neuronal activity during general anesthesia, specific to the primary population of cortical output neurons. We demonstrate that this increased correlation reduces the information output from cortex, suggesting a mechanism for the loss of consciousness.

Cannabis consumption, particularly among adolescents, has surged over the last decades. Adolescence is a critical period for brain development during which the prefrontal cortex (PFC) completes its maturation. There is strong evidence that the endocannabinoid system is a key regulator of brain development and of maturation of the PFC during adolescence. However, whether chronic cannabinoid receptor activation during this stage of development has long-term consequences for PFC function and associated behaviors remains unexplored. Here we show that repeated injection of cannabinoid receptor agon

The medial prefrontal cortex (mPFC) is important for higher cognitive functions. In vivo recordings of neuronal activity in the mPFC have been achieved via invasive electrical and optical approaches. Recently developed three-photon (3P) in vivo imaging enables deeper tissue penetration than two-photon microscopy. Here, we demonstrate high resolution structural and functional 3P-imaging in the mPFC of the mouse at unprecedented depth. Specifically, we perform Ca2+-imaging in awake head-fixed mice up to a depth of 1700 µm in the mPFC. We record Ca2+-transients in neurons, astrocytes and longitud