Biology subjects

Kitano, K.

Publications and source records attributed to Kitano, K..

3 recordsLinked to original sources

bioRxiv2022

Design of the mammalian cone photoreceptor to Off bipolar cell synapse

Graded synapses in sensory systems reliably transmit small signals in the presence of continuous quantal noise. To understand how signaling is optimized during graded transmission, we counted the number of vesicles released by a mammalian cone terminal and compared it to the simultaneous responses in each Off bipolar cell type. Off bipolar cells contacting the terminal base comprised two groups depending on how they sampled transmitter release. In both groups, responses initially grew non-linearly with the number of released vesicles implicating a role for cooperativity during sparse release. One group sampled release from most of a cones [~]20 ribbons and can exploit averaging to improve signal reliability. The other, less-sensitive group made 1-3 contacts at the terminal center and responded to pooled transmitter, a consequence of membrane depolarization, using an insensitive kainate receptor. Off bipolar cells use different strategies to minimize transmission noise and encode cone output over different ranges.

neuroscience↗

bioRxiv2020

Helping Behavior in Prairie Voles: A Model of Empathy and the Importance of Oxytocin

Several studies suggest that rodents show empathic responses and helping behavior toward others. We examined whether prairie voles (Microtus ochrogaster) would help conspecifics who were soaked in water by opening a door to a safe area. Door-opening latency decreased as task sessions progressed. When the conspecific was not soaked in water, the latency of the door-opening did not decrease, indicating that the distress of the conspecific is necessary for the learning of the door-opening. These suggest that prairie voles learn helping behavior. We found no sex difference in the door-opening latency or the interest in other voles soaked in water. Additionally, we also examined the helping behavior in prairie voles in which oxytocin receptors were genetically knocked out. Oxytocin receptor knockout voles demonstrated less learning of the door-opening and less interest in other voles soaked in water. This suggests that oxytocin is important for the emergence of helping behavior.

animal behavior and cognition↗

bioRxiv2018

Reconstructing Neuronal Circuitry from Parallel Spike Trains

State-of-the-art techniques allow researchers to record large numbers of spike trains parallel for many hours. With enough such data, we should be able to infer the connectivity among neurons. Here we develop a computationally realizable method for reconstructing neuronal circuitry by applying a generalized linear model (GLM) to spike crosscorrelations. Our method estimates interneuronal connections in units of postsynaptic potentials and the amount of spike recording needed for verifying connections. The performance of inference is optimized by counting the estimation errors using synthetic data from a network of Hodgkin-Huxley type neurons. By applying our method to rat hippocampal data, we show that the numbers and types of connections estimated from our calculations match the results inferred from other physiological cues. Our method provides the means to build a circuit diagram from recorded spike trains, thereby providing a basis for elucidating the differences in information processing in different brain regions.

neuroscience↗