"Neuromodulation plays a fundamental role in the acquisition of new behaviours. In previous
experimental work, we showed that acetylcholine biases hippocampal synaptic plasticity towards
depression, and the subsequent application of dopamine can retroactively convert depression into
potentiation. We also demonstrated that incorporating this sequentially neuromodulated Spike-
Timing-Dependent Plasticity (STDP) rule in a network model of navigation yields effective learning
of changing reward locations. Here, we employ computational modelling to further characterize the
effects of cholinergic depression on behaviour. We find that acetylcholine, by allowing learning from
negative outcomes, enhances exploration over the action space. We show that this results in a variety
of effects, depending on the structure of the model, the environment and the task. Interestingly,
sequentially neuromodulated STDP also yields flexible learning, surpassing the performance of other
reward-modulated plasticity rules."
Reference:
1 .
Zannone S, Brzosko Z, Paulsen O, Clopath C (2018) Acetylcholine-modulated plasticity in reward-driven navigation: a computational study. Sci Rep 8:9486 [PubMed]
|
