Bat and Bird Songs for Systems Neuroscience

This week’s Science features an article about the songs of bats - not the ultrasonic echolocating calls most often associated with these wonderful creatures but complex vocalizations that bats use socially.

The most well-studied “songsters,” as the author, Virginia Morell, calls them, are songbirds. In species like canaries, zebra finches and starlings, the male sings a courtship song that he learns from his father to woo females.

How does sensory experience change cortex?

The neocortex is an evolutionarily new part of the brain unique to mammals and is responsible for high level sensation, movement and cognition. It wouldn't be fair to summarize in a sentence or two what cortex "does," but it is clear that it is an important part of the brain. Korbinian Brodmann famously divided the human cortex into about 50 areas based on histology of the six cortical layers in different parts of the brain; Brodmann's areas are still used today because their functions follow their histological structure. While cortical areas have largely stereotyped wiring patterns, some connectivity “motifs” are thought to be area-specific, varying based on the type of input the area receives. It is unknown whether the type of input (i.e. statistics of incoming activity that vary with types of sensory stimuli) to a given cortical area determines the types of connectivity motifs present in that region. And while classical cortical “rewiring”experiments from Mriganka Sur’s lab have shown that primary sensory cortices are somewhat tolerant to process foreign inputs, it is not clear to what extent those circuits constitute basic computational units or if foreign inputs cause reorganization of connections within the circuit.