Skip to main content Skip to search
Details
Displaying 1 - 6 of 6
The hippocampus and cerebral neocortex receive massive cholinergic projections from the basal forebrain. These projections arise predominantly within the nucleus basalis of Meynert, also known as the Ch4 cell group. The cholinergic projection of the cerebral cortex plays a major role in sustaining episodic memory, attention, and experience-induced neuroplasticity. Progressive neurofibrillary degeneration in the nucleus basalis can be seen throughout the continuum that leads from normal aging to mild cognitive impairment and Alzheimer’s disease. The resultant perturbation of cortical cholinergic neurotransmission may contribute to the cognitive changes seen in normal aging and Alzheimer’s disease.

Neuroimaging and neurological investigations have shown that the frontal lobes play a critical role in human memory. In many aspects of memory, including working memory, learning of new information, and retrieval, the frontal lobes contribute to the guidance or executive control of memory processing. With the dynamic interplay of broad neural circuits, this brain region facilitates in the selecting, maintaining, updating, and retrieval of memory. In its absence, memories are disorganized and easily disrupted by interference or distraction. Terms such as executive control, top-down processing, and metacognitive control have been used to characterize the role of the frontal lobes in memory processes.

Neuroimaging and neurological investigations have shown that the frontal lobes play a critical role in human memory. In many aspects of memory, including working memory, learning of new information, and retrieval, the frontal lobes contribute to the guidance or executive control of memory processing. With the dynamic interplay of broad neural circuits, this brain region facilitates in the selecting, maintaining, updating, and retrieval of memory. In its absence, memories are disorganized and easily disrupted by interference or distraction. Terms such as executive control, top-down processing, and metacognitive control have been used to characterize the role of the frontal lobes in memory processes.

The prefrontal cortex in primates occupies the anterior part of the frontal lobe on the lateral, medial, and basal surfaces of the brain. Most prefrontal areas have six layers, including a granular layer IV, except for posterior orbitofrontal and medial prefrontal areas, which have fewer than six layers and belong to the cortical limbic system. Prefrontal cortices receive projections from a large variety of sensory association and polymodal cortices, have strong connections with the mediodorsal thalamic nucleus, and have direct access to cortical and subcortical motor control systems. Lateral prefrontal cortices are connected with temporal and parietal areas associated with cognitive functions, while orbitofrontal and anterior cingulate areas have robust connections with the amygdala and medial temporal structures associated with emotions and memory. Connections between distinct prefrontal areas suggest that they collaborate in behavior.