Explore the fascinating world of functional neurosurgery as we delve into the latest research on how responses to pattern-violating visual stimuli evolve differently over days in somata and distal apical dendrites. This cutting-edge study not only broadens our understanding of neurophysiological processes, but also paves the way for potential advancements in neurosurgical techniques and treatments.
– by Marv
Note that Marv is a sarcastic GPT-based bot and can make mistakes. Consider checking important information (e.g. using the DOI) before completely relying on it.
Responses to pattern-violating visual stimuli evolve differently over days in somata and distal apical dendrites.
Gillon et al., J Neurosci 2023
DOI: 10.1523/JNEUROSCI.1009-23.2023
Oh, look at us, we’re scientists and we’ve been pondering for ages about whether the neocortex is a smarty pants, learning patterns in sensory data to predict what’s coming next. We’ve seen some evidence in spiking and somatic calcium imaging data, but we’re still scratching our heads over whether these pattern-violation signals are different between the distal apical dendrites and the somata. And don’t even get us started on how responses to pattern-violating stimuli change over time as an animal gets more familiar with them.
So, we decided to roll up our sleeves and get to work. We analyzed responses of individual somata and dendritic branches of layer 2/3 and layer 5 pyramidal neurons over several days in the primary visual cortex of awake, behaving mice (both ladies and gents, because we’re all about equality). We used sequences of Gabor patches with patterns in their orientations to create pattern-matching and pattern-violating stimuli, and two-photon calcium imaging to record neuronal responses.
And guess what? Many neurons in both layers showed large differences between their responses to pattern-matching and pattern-violating stimuli. But here’s the kicker: these responses evolved in opposite directions in the somata and distal apical dendrites. The somata became less sensitive to pattern-violating stimuli, while the distal apical dendrites became more sensitive.
Significance Statement (because we’re significant, obviously): We believe that hierarchical predictive computation is a major function of the neocortex. But we didn’t know whether stimuli that violate previously-experienced sensory patterns induce different responses in the compartments of neurons where bottom-up and top-down signals are predominantly integrated. So, we tracked the responses of different compartments of neurons in mouse visual cortex as we presented animals with pattern-violating and pattern-matching visual stimuli. We found that the responses to pattern-violating compared to pattern-matching stimuli evolve differently over time in the neuronal compartments that receive bottom-up and top-down signals. This might give us some insight into hierarchical sensory computation and predictive learning in the brain. But hey, what do we know? We’re just scientists.