Serotonin Decreases the Gain of Visual Responses in Awake Macaque V1

• DOI: 10.1523/jneurosci.1339-17.2017
• Publication Date: 2017-10-18T00:25:24Z
• Authors: Lenka Seillier; Corinna Lorenz; Katsuhisa Kawaguchi; Torben Ott; Andreas Nieder; Paria Pourriahi; Hendrikje Nienborg
• Keywords: Stimulus (psychology)

Serotonin, an important neuromodulator in the brain, is implicated affective and cognitive functions. However, its role even for basic cortical processes controversial. For example, mammalian primary visual cortex (V1), heterogenous serotonergic modulation has been observed anesthetized animals. Here, we combined extracellular single-unit recordings with iontophoresis awake We examined of serotonin on well-defined tuning properties (orientation, spatial frequency, contrast, size) V1 two male macaque monkeys. find that modulatory effect surprisingly uniform: it causes a mainly multiplicative decrease responses slight increase stimulus-selective response latency. Moreover, neither systematically changes selectivity or variability response, nor interneuronal correlation unexplained by stimulus (“noise-correlation”). The qualitative similarities but differs quantitatively from decreasing contrast. It can be captured simple additive change to threshold-linear spiking nonlinearity. Together, our results show well suited control gain neurons depending animal's behavioral motivational context, complementing other known state-dependent gain-control mechanisms. SIGNIFICANCE STATEMENT Serotonin brain major target drugs used treat psychiatric disorders. Nonetheless, little about how shapes information processing sensory areas. Here behaving found decreased responses, without changing their selectivity, variability, covariability. This identifies computational function processing, state.