Neuroplasticity: How the brain adapts and learns

For centuries, medical science and classical psychology operated under the dogma that the human brain was a rigid organ, endowed with an unchanging structure after the end of early childhood. It was believed that we would be born with a predetermined number of neurons and synaptic connections that would inevitably degrade over time, leaving subjects to accept intellectual limitations or brain damage as irreversible conditions. Fortunately, contemporary neuroscience has refuted this static view with the consolidation of the concept of neuroplasticity (or brain plasticity), demonstrating that the central nervous system is a dynamic, adaptable and continually changing system.

"Neuroplasticity is the capacity for morphological and functional modification of the nervous system in response to environmental stimuli, experiences and new learning throughout the subject's life." — Roberto Lent (2013, p. 112)

Mechanisms and Classifications of Neuroplasticity

The brain reconfigures itself on multiple levels to adjust to new external and internal demands. According to neurophysiological research by Savassini (2019), neural plasticity can be classified according to the phase of development in which it occurs:

• Ontogenetic Plasticity: It is the highly intense plasticity that occurs during embryonic and immediate postnatal development. At this stage, the environment plays a determining role in the initial physical wiring of neural circuits, sculpting connections according to the stimuli received.
• Adult Plasticity: Although less vigorous than ontogenetics, it is the capacity that remains throughout adult life and in senescence, allowing continuous learning, the acquisition of new habits and cognitive reserve in the face of aging.

Regardless of age group, neuroplasticity essentially manifests itself in three interconnected ways (LENT, 2013):

1. Morphological (or Structural): It involves physical changes in brain architecture, such as the sprouting of new cellular processes (dendrites), the physical formation of new synapses (synaptogenesis) or the elimination of redundant or underused connections (synaptic pruning).
2. Physiological (or Synaptic): It refers to the change in the chemical efficiency of information transmission between neurons. When two neural cells fire together repeatedly, the strength of their connection increases, a phenomenon called Long-Term Potentiation (LTP).
3. Functional (or Mapping): It is the brain's ability to reorganize its cortical maps. If a brain region suffers an injury (as in a stroke), neighboring or homologous areas in the opposite hemisphere may fully or partially take over the lost function (vicariance).

Synaptic Plasticity and Memory Consolidation

The cellular basis of learning lies in synaptic plasticity. The conversion of short-term memories into stable long-term memories occurs through a feedback loop centered on the brain. hippocampus, a structure that acts as a gateway and selector of information (SQUIRE; KANDEL, 2003). THE Long Term Potentiation (LTP) it is the molecular mechanism that consolidates these memories.

During learning, repeated electrical stimuli release the excitatory neurotransmitter glutamate in the synaptic cleft. Glutamate binds to specific receptors on the membrane of the postsynaptic neuron: the receptors AMPA (which generate quick responses) and the receptors NMDA (which act as coincidence detectors). When the stimulation is strong enough, the NMDA channel opens, allowing the massive entry of calcium ions into the cell. This influx of calcium triggers biochemical cascades that activate genes in the cell nucleus, stimulating the synthesis of new proteins and generating the insertion of more AMPA receptors in the membrane. The physical result is a permanently strengthened synapse, facilitating future firing with less electrical energy.

Implications for Psychopedagogical Intervention

For Psychopedagogy and Clinical Neuropsychopedagogy, plasticity is the scientific validation of therapeutic practice. Subjects who have specific learning difficulties or neurodevelopmental disorders (such as Dyslexia and ADHD) have atypical patterns of brain activation in circuits dedicated to reading or inhibitory control.

Psychopedagogical intervention not only aims to overcome the problem, but actively stimulate compensatory plasticity. Through systematic and intentional phonological training activities, sustained attention and logical-mathematical reasoning, the therapist stimulates the formation of alternative neural routes. With time and consistency of treatment, neuroimaging exams demonstrate a normalization in the cortical activation of these students, proving that the brain structure was physically reorganized by psychopedagogical stimulation.

Comparison of Neuroplasticity Levels

The table below comparatively describes the three fundamental levels of brain plasticity and its main practical manifestations in learning:

Plasticity Level	Main Biological Mechanism	Relevance to Learning
Synaptic Plasticity (Physiological)	Increase or decrease in the release of neurotransmitters and the density of postsynaptic receptors (LTP/LTD).	Rapid change in the efficiency of connections, allowing the immediate acquisition of new memories and isolated facts.
Structural (Morphological) Plasticity	Budding of new dendritic buds, axon growth, physical synaptogenesis and axon myelination.	Long-term consolidation of learned skills (e.g. reading fluently, playing an instrument automatically).
Functional Plasticity (Mapping)	Reorganization of cortical areas and recruitment of healthy hemispheres to compensate for deficient functions.	Recovery of cognitive functions after injuries or rehabilitation of severe neurodevelopmental disorders.

Active Study Methods Based on Neuroplasticity

Understanding the neurobiology of learning requires the adoption of study methodologies that maximize the activation of postsynaptic receptors and accelerate the consolidation of memories:

1. Active Recall: Reading a text repeatedly or watching video classes passively generates little plasticity (low LTP). The brain needs to be forced to retrieve information from memory. Making memory cards (flashcards), answering questionnaires and explaining the content in your own words forces the reactivation of neural circuits, strengthening the synapses involved.
2. Spaced Repetition: Trying to accumulate all the studying the day before a test generates intense, but temporary, synaptic activation. Stable consolidation of neuronal pathways requires time and repetition distributed over days. Sleep is the essential physiological phase in which the brain transfers temporary memory from the hippocampus to the neocortex (stable consolidation).
3. Intelligent Use of Error: From a neurological point of view, the error is a chemical warning signal. When making a mistake and immediately seeking the correct answer, the brain releases neuromodulatory neurotransmitters (such as dopamine and noradrenaline) that signal to the neural circuit that the previous response was inadequate, facilitating the reconfiguration of synaptic weights and the retention of correct learning.