Neuroanatomical investigations of the projections of the Papez circuit, with an emphasis on connections to the diencephalon

The projections of the extended hippocampal formation are still to a surprising extent under-described and under-investigated, despite the Papez circuit having been first postulated in 1937.  James Papez originally proposed that “the hypothalamus, the anterior thalamic nuclei, the gyrus cinguli, the hippocampus and their interconnections constitute a harmonious mechanism which may elaborate the functions of central emotion,… Read More

Exploring adverse neuropsychiatric effects of interferon alpha, using a preclinical model; exploring behavioural and pharmacological pathways to amelioration of these adverse effects

Recombinant Human Interferon-Alpha Pic from the Wikimedia Commons. Interferon alpha is widely used in the treatment of a variety of non-neurological conditions (for example, hepatitis C, Kaposi’s sarcoma, among others). It is in fact currently the only FDA-approved treatment for hepatitis C. Treatment for hepatitis is limited by the striking and adverse neuropsychiatric consequences of interferon alpha… Read More

Roles for the cyclooxygenases (especially COX 2) in learning and memory, as well as in synaptic plasticity.

A pair of papers which focus on the role the inducible inflammatory regulating enzyme COX2 plays in learning and memory. These papers proceeded from earlier work of ours, showing that the bacterial endotoxin lipopolysaccharide (LPS) blocked synaptic plasticity but not synaptic transmission CA1-subiculum pathway in vivo. LPS induces the expression of COX2, amongst other things, and it seemed reasonable to… Read More

Roles for the subiculum in spatial information processing, memory, motivation and the temporal control of behaviour.

Take-home message: The subiculum is in a pivotal position governing the output of the hippocampal formation. Despite this, it is a rather under-explored and sometimes ignored structure. Here, we discuss recent data indicating that the subiculum participates in a wide range of neurocognitive functions and processes. More research required! [Download the paper] Roles for the subiculum… Read More

Impaired capacity for autonoetic reliving during autobiographical event recall in mild Alzheimer’s disease

Take-home message: Autonoesis or ‘Autonoetic consciousness is the human ability to mentally place ourselves in the past, in the future, or in counterfactual situations, and to analyze our own thoughts‘ (wiki). Here, we focus on impairments of autonoesis in Alzheimer’s disease (AD), using the Episodic Autobiographical Memory Interview (EAMI). We find impairments in AD patients with the following pattern: AD [Download the paper]… Read More

Theta-modulated head direction cells in the rat anterior thalamus.

Take-home message – two key findings: (1) there are head-direction cells in the anteroventral thalamus (head direction cells fire when the head is pointed in a particular orientation); (2) a large fraction of these cells are theta-modulated (a strong 7-12 Hz oscillation in the EEG, studied most frequently in the hippocampal formation). These data are interesting because they suggests that the anterior thalamus… Read More

Prolonged rote learning produces delayed memory facilitation and metabolic changes in the hippocampus of the ageing human brain.

Take-home message: repeated practice with material that must be remembered facilitates remembering in an aged population in whom there is expected to be a degree of age-related memory loss. This practice produces changes in the brain in structures that support learning and memory. Think of it like this: memory can be exercised via practice, much… Read More

Exploring the recollective experience during autobiographical memory retrieval in amnestic mild cognitive impairment.

Take-home message: there are greater levels of autobiographical memory (memory for the episodes and events of your life and general knowledge of the world) impairment in amnestic mild cognitive impairment (aMCI: a greater than expected deficit in cognitive function for age and education) seen than previously assumed. More on MCI, which is often thought of as being prodromal for Alzheimer’s disease (AD), as a proportion of… Read More

Hippocampal-anterior thalamic pathways for memory: uncovering a network of direct and indirect actions.

Our major theoretical take and review of the extended brain systems that support explicit, declarative memory in the brain. [Download the paper.] Take-home message: there’s a lot more to memory than the hippocampal formation, and you forget (!) the connected thalamic structures at your peril, because the anterior thalamus provides a subcortical circuit supporting memory and spatial… Read More

Aerobic exercise improves hippocampal function and increases BDNF in the serum of young adult males.

Take-home message: It is becoming increasingly accepted that substantial, sustained low-impact aerobic exercise has profound effects on neurocognitive function in the aged (see, for example, this very important paper from Art Kramer’s group). We here focus on a young and sedentary population, using tasks that tap into hippocampal function. We also measure circulating brain-derived neurotrophic factor (BDNF) as a proxy for brain BDNF. We… Read More