Learning and memory
Neurons create and store ‘memories’ to control cognitive function. Persistent activation of a neuronal synapse results in long-term potentiation (LTP) that underlies learning and memory. Neuronal synapse activation initiates a cascade of LTP a cascade as follows:
1) Early-phase LTP via PTMs (ex. phosphorylation of calmodulin-kinase II or CaMKII)
2) Late phase LTP via gene activation
3) LTP maintenance via gene activation (from influx of calcium and calcium-dependent proteins)
3A) LTP maintenance via immediate early genes (IEGs)
Alterations in histone modifications and DNA methylation in the central nervous system (CNS) correlate with learning and memory consolidation. Inhibition of CRFs that impose marks correlates with diminished cognitive ability.
Short vs long-term memory
Cortex (long) vs. hippocamus (short)
This ability to hold on to a piece of information temporarily in order to complete a task is specifically human. It causes certain regions of the brain to become very active, in particular the pre-frontal lobe.
Information is transferred from short-term memory (also known as working memory) to long-term memory through the hippocampus, so named because its shape resembles the curved tail of a seahorse (hippokampos in Greek). The hippocampus is a very old part of the cortex, evolutionarily, and is located in the inner fold of the temporal lobe.
All of the pieces of information decoded in the various sensory areas of the cortex converge in the hippocampus, which then sends them back where they came from. The hippocampus is a bit like a sorting centre where these new sensations are compared with previously recorded ones. The hippocampus also creates associations among an object’s various properties.
1) Early-phase LTP via PTMs (ex. phosphorylation of calmodulin-kinase II or CaMKII)
2) Late phase LTP via gene activation
3) LTP maintenance via gene activation (from influx of calcium and calcium-dependent proteins)
3A) LTP maintenance via immediate early genes (IEGs)
- transcription factors that encode components of neuronal dendridic spines that form between neurons to increase synapse number and strength
- TFs that form 'post-synaptic density' that concentrates neurotransmitter receptors
Alterations in histone modifications and DNA methylation in the central nervous system (CNS) correlate with learning and memory consolidation. Inhibition of CRFs that impose marks correlates with diminished cognitive ability.
Short vs long-term memory
Cortex (long) vs. hippocamus (short)
This ability to hold on to a piece of information temporarily in order to complete a task is specifically human. It causes certain regions of the brain to become very active, in particular the pre-frontal lobe.
Information is transferred from short-term memory (also known as working memory) to long-term memory through the hippocampus, so named because its shape resembles the curved tail of a seahorse (hippokampos in Greek). The hippocampus is a very old part of the cortex, evolutionarily, and is located in the inner fold of the temporal lobe.
All of the pieces of information decoded in the various sensory areas of the cortex converge in the hippocampus, which then sends them back where they came from. The hippocampus is a bit like a sorting centre where these new sensations are compared with previously recorded ones. The hippocampus also creates associations among an object’s various properties.