From the FDA Drug Label
Current theories on the pathogenesis of the cognitive signs and symptoms of Alzheimer’s disease attribute some of them to a deficiency of cholinergic neurotransmission. Persistent activation of central nervous system N-methyl-D-aspartate (NMDA) receptors by the excitatory amino acid glutamate has been hypothesized to contribute to the symptomatology of Alzheimer’s disease
The biochemical basis of memory is related to cholinergic neurotransmission and glutamate. Donepezil hydrochloride is postulated to exert its therapeutic effect by enhancing cholinergic function through reversible inhibition of acetylcholinesterase, while memantine is postulated to exert its therapeutic effect through its action as a low to moderate affinity uncompetitive NMDA receptor antagonist.
- Key components involved:
- Cholinergic neurotransmission
- Glutamate
- Acetylcholinesterase
- NMDA receptors
- Mechanisms of action:
From the Research
The biochemical basis of memory involves a tripartite mechanism consisting of interactions between neurons, their neural extracellular matrix, trace metals, and neurotransmitters, as proposed in the most recent study 3. This mechanism is crucial for linking physiological responses, including sensations, with affective states such as emotions. The process of memory formation is complex and involves various molecular processes in neurons that allow information storage and retrieval.
- Key aspects of memory formation include:
- Neurotransmitter release at synapses, primarily involving glutamate binding to NMDA and AMPA receptors
- Activation of signaling cascades, including calcium/calmodulin-dependent protein kinase II (CaMKII), protein kinase C (PKC), and cAMP-dependent protein kinase A (PKA)
- Phosphorylation of proteins and activation of transcription factors like CREB (cAMP response element-binding protein), leading to gene expression changes
- Temporary protein modifications for short-term memory and protein synthesis and structural changes at synapses for long-term memory through long-term potentiation (LTP) and long-term depression (LTD)
- The role of omega-3 fatty acids, particularly docosahexaenoic acid (DHA), in cognitive function and memory has been highlighted in recent studies 4, 5, suggesting a potential protective effect against cognitive impairment and Alzheimer's disease.
- Understanding the biochemical mechanisms of memory has significant implications for treating memory disorders and developing cognitive enhancers that target specific pathways in this complex molecular machinery, as discussed in various studies 6, 7.