The hippocampus integrates context and shock into a configural memory in contextual fear conditioning.

Contextual fear conditioning involves forming a representation for the context and associating it with a shock, which were attributed by the prevailing view to functions of the hippocampus and amygdala, respectively. Yet our recent evidence suggested that both processes require integrity of the dorsal hippocampus (DH). In view of the DH involvement in uniting multiple stimuli into a configuration, this study examined whether the DH would integrate context and shock into a shocked-context representation.

Roles of hippocampal GABA(A) and muscarinic receptors in consolidation of context memory and context-shock association in contextual fear conditioning: a double dissociation study.

Contextual fear conditioning involves forming a context representation and associating it to a shock, both of which involved the dorsal hippocampus (DH) according to our recent findings. This study tested further whether the two processes may rely on different neurotransmitter systems in the DH. Male Wistar rats with cannula implanted into the DH were subjected to a two-phase training paradigm of contextual fear conditioning to separate context learning from context-shock association in two consecutive days.

Sex differences in high-fat diet-induced obesity, metabolic alterations and learning, and synaptic plasticity deficits in mice.

Obesity is a potential risk factor for cognitive deficits in the elder humans. Using a high-fat diet (HFD)-induced obese mouse model, we investigated the impacts of HFD on obesity, metabolic and stress hormones, learning performance, and hippocampal synaptic plasticity. Both male and female C57BL/6J mice fed with HFD (3 weeks to 9-12 months) gained significantly more weights than the sex-specific control groups.

Infusion of lidocaine into the dorsal hippocampus before or after the shock training phase impaired conditioned freezing in a two-phase training task of contextual fear conditioning.

Learning in a contextual fear conditioning task involves forming a context representation and associating it with a shock. The dorsal hippocampus (DH) is implicated in representing the context, but whether it also has a role in associating the context and shock is unclear. To address this issue, male Wistar rats were trained on the task by a two-phase training paradigm, in which rats learned the context representation on day 1 and then reactivated it to associate with the shock on day 2; conditioned freezing was tested on day 3.