Hiramoto, M. | Search bioRxiv

bioRxiv2024

Visual neurons recognize complex image transformations

Natural visual scenes are dominated by sequences of transforming images. Spatial visual information is thought to be processed by detection of elemental stimulus features which are recomposed into scenes. How image information is integrated over time is unclear. We explored visual information encoding in the optic tectum. Unbiased stimulus presentation shows that the majority of tectal neurons recognize image sequences. This is achieved by temporally dynamic response properties, which encode complex image transitions over several hundred milliseconds. Calcium imaging reveals that neurons that encode spatiotemporal image sequences fire in spike sequences that predict a logical diagram of spatiotemporal information processing. Furthermore, the temporal scale of visual information is tuned by experience. This study indicates how neurons recognize dynamic visual scenes that transform over time. One-Sentence SummaryComplex visual scenes are encoded by plastic trajectories of spatiotemporal image sequences.

neuroscience↗

bioRxiv2022

Postsynaptic receptors regulate presynaptic neurotransmitter stability

Stable matching of neurotransmitters with their receptors is fundamental to synapse function, to achieve reliable and robust communication in neural circuits. Presynaptic neurotransmitters regulate selection of postsynaptic transmitter receptors. However, whether postsynaptic receptors regulate selection of presynaptic transmitters is unknown. Here we show that blockade of postsynaptic acetylcholine receptors at the neuromuscular junction leads to loss of the cholinergic phenotype in motor neurons and stabilization of an earlier, developmentally transient glutamatergic phenotype. Exogenous postsynaptic expression of GABAA receptors leads to the stabilization of an earlier, developmentally transient GABAergic motor neuron phenotype. Both acetylcholine receptors and GABA receptors are linked to presynaptic neurons through trans-synaptic bridges. Knock-down of different components of these trans-synaptic bridges prevents stabilization of the cholinergic and GABAergic phenotypes. We conclude that this bidirectional communication enforces a match between transmitter and receptor and ensures the fidelity of synaptic transmission. Our findings suggest a role of dysfunctional transmitter receptors in neurological disorders that involve the loss of the presynaptic transmitter.

neuroscience↗