1. Stage of dominant motivation
The initial stage is the fundamental basis for fixing any data. The process is triggered by powerful ascending influences originating from the hypothalamus and other subcortical structures. These signals are directed to the brain, where their primary target is cortical pyramidal neurons.
Under the influence of activating impulses, a number of crucial events unfold at the cellular level:
- There is a significant expansion of the convergent properties of nerve cells, allowing them to receive and integrate signals from multiple diverse sources.
- The baseline sensitivity of membranes to specific chemical mediators—neurotransmitters and oligopeptides—changes.
- Primary molecular cascades are triggered, expressed as enhanced expression of so-called early genes.
2. Stage of short-term memory
Following initial activation, information must be retained in the nervous system for further processing. This process is ensured by a special neurodynamic phenomenon: reverberation.
Reverberation is the continuous circulation of nerve excitation through closed loops of neurons. This "running in circles" of nerve impulses occurs not chaotically, but along strict routes:
- Within the cerebral cortex itself.
- Along complex pathways connecting the cortex with various subcortical structures.
3. Stage of long-term memory (Consolidation)
The transfer of information into permanent storage is called consolidation. For this transition to occur, one critically important condition is required: the application of reinforcement. The reinforcing factor can be the satisfaction of a basic biological need or the attainment of a socially significant result.
If a reinforcement factor is present, deep biochemical and structural reorganizations are initiated in the nervous tissue:
- A powerful activation of the genetic apparatus of brain cells occurs. Notably, not only neurons themselves participate in this process, but also glial cells.
- At the cellular level, the expression of late genes increases manifold.
- The ultimate outcome of genetic activity is the synthesis of specific informational (protein) molecules. It is these newly created molecules that are necessary for the reliable physical fixation of the memory trace in brain structures.
Briefly: answers to topical questions
Which specific early and late genes are expressed during memory trace consolidation?
During memory trace consolidation and behavioral shaping, specific early genes are reliably expressed, whereas the names of specific late genes are not cited. The involvement of the following genes is known:
- Early genes (c-fos, c-jun) — activated at the stage of dominant motivation to form the orienting-investigatory response and precede protein synthesis.
- Late genes — activated after reinforcement and ensure the synthesis of effector proteins for goal-directed behavior (specific names are absent in the materials).
What specific proteins are synthesized to fix the memory trace at the genetic level?
To fix the memory trace at the genetic level, the sources do not provide exact chemical names of individual proteins. The following groups and designations are indicated:
- Specific protein molecules / specific polypeptides — synthesized during learning and reinforcement.
- Brain-specific proteins, or "memory proteins".
- New components of synaptic membranes, especially glycoproteins.
These proteins stabilize primary changes in synaptic membranes, can embed into synaptic membranes, or alter the neuron structure, ensuring long-term plasticity and consolidation of the memory trace. Within a few hours, an increase in the synaptic contact zone and an increase in the number of dendritic spines are described.
For quick memorization of the key sequence, use the "MRC" rule: Motivation (cortical activation) → Reverberation (impulse circulation) → Consolidation (reinforcement and protein synthesis).
Class and exam questions
What changes occur in cortical pyramidal neurons at the very first stage of memorization?
In pyramidal neurons, convergent properties expand, receptor sensitivity to neurotransmitters and oligopeptides changes, and early gene expression increases.
What is the mechanism of information retention in short-term memory?
The basis is reverberation—the process of continuous circulation of nerve impulses through closed neural circuits within the cortex, as well as between the cortex and subcortical centers.
What is a mandatory condition for triggering memory trace consolidation?
A mandatory condition is the presence of biological or socially significant reinforcement, for example, the satisfaction of a need or the achievement of an important result.
Which brain cells, besides neurons, actively participate in the formation of long-term memory?
Glial cells actively participate in the activation of the genetic apparatus and the synthesis of specific informational molecules during the consolidation stage.
What else to study on this topic
- Mechanisms of ascending activating influences of the hypothalamus
- Convergent properties of cerebral cortex neurons
- Physiological role of early and late genes in nervous tissue
- Biochemical nature of specific informational memory molecules
- Interaction of neurons and neuroglia in higher nervous activity
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