Direction of motion decoding in mouse V1: Neuron predictive power relates to functional connectivity organization

Mario Alexios Savaglio, Maria Papadopouli

Keywords: stimulus decoding, functional connectivity, neuronal ensembles, area V1, direction of motion

Abstract:

Variability in single neuron responses presents a
challenge in establishing reliable representations of visual stimuli
essential for driving behavior. To enhance accuracy, integration
of responses from multiple neurons is imperative. This study
leverages simultaneous recordings from a large population (tens
of hundreds) of neurons, achieved through in vivo mesoscopic
2-photon calcium imaging of the primary visual cortex (V1)
in mice, under visual stimulus conditions as well as in resting
state (absence of stimulus). The visual stimulus consisted of
16 distinct randomly shuffled directions of motion presented to
the mice. We employed mutual information to identify neurons
that contain the most significant information about the stimulus
direction. As expected, neurons displaying high predictive power
(HPP) in stimulus decoding exhibit elevated firing event rates
during stimulus presentation. Furthermore, functional connec-
tivity among HPP neurons during visual stimulation is denser
and stronger compared to functional connectivity among other
visually responsive neurons. Functional connections among HPP
neurons appear to form independently of distance, suggesting
a distributed yet highly coordinated network. In contrast, HPP
neuronal activity and functional connectivity differed significantly
at resting state. Specifically, during the resting state, HPP neurons
exhibited lower event rates and functional connectivity structure
that was not significantly different from that of other visually
responsive neurons. This suggests that HPP neurons are less
susceptible to being driven simultaneously by internal brain states
in the absence of a stimulus. Finally, the tuning properties of
HPP neurons were unexpectedly diverse: while some were sharply
tuned, others conveyed a similar amount of mutual information,
despite exhibiting much weaker tuning. This study sheds light on
the organization of neuronal ensembles important for decoding
visual motion direction in mouse area V1, contributing to the
understanding of information processing in mouse visual cortex.

Submission Number: 112