Reversal learning reveals cognitive deficits and altered prediction error encoding in the ventral striatum in Huntington's disease.

Huntington's disease (HD) is an autosomal dominant neurodegenerative condition characterized by a triad of movement disorder, neuropsychiatric symptoms and cognitive deficits. The striatum is particularly vulnerable to the effects of mutant huntingtin, and cell loss can already be found in presymptomatic stages. Since the striatum is well known for its role in reinforcement learning, we hypothesized to find altered behavioral and neural responses in HD patients in a probabilistic reinforcement learning task performed during functional magnetic resonance imaging.

Reversal learning strategy in adolescence is associated with prefrontal cortex activation.

Adolescence is a critical maturation period for human cognitive control and executive function. In this study, a large sample of adolescents (n = 85) performed a reversal learning task during functional magnetic resonance imaging. We analyzed behavioral data using a reinforcement learning model to provide individually fitted parameters and imaging data with regard to reward prediction errors (PE).

Gating of hippocampal output by β-adrenergic receptor activation in the pilocarpine model of epilepsy.

Norepinephrine acting via β-adrenergic receptors (β-ARs) plays an important role in hippocampal plasticity including the subiculum which is the principal target of CA1 pyramidal cells and which controls information transfer from the hippocampus to other brain regions including the neighboring presubiculum and the entorhinal cortex (EC). Subicular pyramidal cells are classified as regular- (RS) and burst-spiking (BS) cells. Activation of β-ARs at CA1-subiculum synapses induces long-term potentiation (LTP) in burst- but not in RS cells (Wójtowicz et al.