Neuroplasticity and Synaptic Strength

• Neuroplasticity refers to the brain's ability to change and reorganize itself throughout a person's life.
• It underlies learning and the brain's ability to repair itself after injury.
• The brain is composed of billions of neurons that communicate through synapses, the spaces between them.
• Neurotransmitters facilitate communication between neurons by transmitting chemical messages across synapses.
• A typical neuron can form thousands of synaptic connections with other neurons, creating intricate networks responsible for various brain functions.
• Synaptic connections and neurons can change over time through neuroplasticity.
• Neuroplasticity is activity-driven, following the "use it or lose it" principle: frequently used synapses strengthen, while rarely used ones weaken or are eliminated.
• New activities stimulate the creation of new neural connections.

Synaptic Strength

• Changes in synaptic strength can be short-term or long-lasting, depending on the intensity and frequency of the signal received.
• Neurons can temporarily strengthen connections by releasing more neurotransmitters, activating new receptors, or modifying existing receptors.
• This is the basis of short-term memory.
• Long-term memory retention needs strong or sustained activity, which will result in structural changes, such as growing new dendritic spines and synaptic connections, or even forming new neurons.
• Structural neuroplasticity can enlarge cortical areas associated with increased activity and shrink areas with less activity.
• An example is that the hand motor region on the left side of the brain is larger in right-handed individuals.

Functional Neuroplasticity and Injury

• Neurons can adopt new functions when sufficiently stimulated.
• Healthy brain tissue can take over functions of damaged areas after a stroke.
• Stress or physical exercise can cause neurons to switch neurotransmitters, often converting them from excitatory to inhibitory or vice versa, leading to behavioral changes.

Phantom Limb Sensation

• Patients who have lost a limb through amputation may still experience sensations from the missing limb. This is called phantom limb sensation.
• Sensory signals from the face may spill over to the inactive arm region in the somatosensory cortex.
• The brain's higher centers misinterpret this as sensation coming from the absent arm.

Neuroplasticity and Age

• Brain plasticity is more pronounced in children because their brains are still developing.
• This is essential for normal brain development, creating functional brain circuits, and learning.
• Acquiring new skills, like languages or musical instruments, is easier in childhood.
• Negative or maladaptive changes due to neuroplasticity can have long-lasting consequences, especially if they occur during childhood - childhood traumas.

Brain Health

• The magnitude of neuroplastic changes depends on the amount of activity the brain receives.
• More practice leads to more learning and keeping the brain active is important for maintaining its health and effectiveness.

Neuroplasticity is the brain's ability to reorganize itself by forming new neural connections. Synaptic connections and neurons can change over time. This process is activity-driven, and follows the "use it or lose it" principle.