neuropeptides, neuroplasticity, neurogenesis

o Mediate slower and more long-lasting synaptic effects when

bound to metabotropic receptors

Neuropeptides

o Most important neuropeptides:

1. Substance P

2. Opioids

3. Hypothalamic releasing hormones

a neurotransmitter of pain and

temperature fibers that synapse in the spinal cord. It

also modulates the immune system and neuronal

activity in times of high stress

1. Substance P –

– have analgesic effects in brain: also inhibits

release of substance P in the spinal cord

2. Opioids

(affect secretory

cells in anterior pituitary) and posterior pituitary

hormones

3. Hypothalamic releasing hormones

• is the ability of neurons to change their

function, chemical profile (quantities and types of

neurotransmitters produced), or structure.

• Involved in learning and creation of new memories

• Essential for recovery from damage to the central nervous

system (CNS)

• It can evolve or adjust

Neuroplasticity

• is the ability of neurons to change their

function, chemical profile (quantities and types of

neurotransmitters produced), or structure.

Neuroplasticity

• Involved in learning and creation of new memories

Neuroplasticity

• Essential for recovery from damage to the central nervous

system (CNS)

Neuroplasticity

• It can evolve or adjust

Neuroplasticity

Neuroplasticity is a general term used to encompass the

following mechanisms:

1. Habituation

2. Experience-dependent plasticity: learning and

memory

3. Cellular recovery after injury

• A decrease in response to a repeated, benign stimulus.

• One of the simplest forms of neuroplasticity and a type of

non-associative learning

• After a period of rest in which the stimulus is no longer

applied, the effects of habituation are no longer present

or are partially resolved, and behavior can be elicited in

response to sensory stimuli.

• Prolonged repetition of stimulation causes permanent

structural changes occur

Ä Habituation in therapy

• Techniques and exercises intended to decrease the neural

response to a stimulus.

o Ex. A child with tactile defensiveness → initiate

treatment by gently stimulating the child’s skin,

then gradually increasing the intensity of

stimulation.

1. Habituation

• A decrease in response to a repeated, benign stimulus.

1. Habituation

• One of the simplest forms of neuroplasticity and a type of

non-associative learning

habituation

• After a period of rest in which the stimulus is no longer

applied, the effects of habituation are no longer present

or are partially resolved, and behavior can be elicited in

response to sensory stimuli.

1. Habituation

• Prolonged repetition of stimulation causes permanent

structural changes occur

1. Habituation

• Complex process involves persistent, long-lasting changes in the strength of synapses between neurons and within neural networks

• Brain activity:

  • Initial phases of motor learning → Large and diffuse

  • Repetition of task → number of activity reduced

  • Motor task learned → small, distinct regions

• requires the synthesis of new proteins, the growth of new synapses, and the modification of existing synapses

Experience-dependent plasticity

• Complex process involves persistent, long-lasting changes in the strength of synapses between neurons and within neural networks

Experience-dependent plasticity

• Brain activity:

  • Initial phases of motor learning → Large and diffuse

  • Repetition of task → number of activity reduced

  • Motor task learned → small, distinct regions

Experience-dependent plasticity

• requires the synthesis of new proteins, the growth of new synapses, and the modification of existing synapses

Experience-dependent plasticity

• Injuries that damage or sever axons cause degeneration

but may not result in cell death.

• Some neurons have the ability to regenerate the axon.

• In contrast to injury to the axon, injuries that destroy the

cell body of a neuron invariably lead to death of the cell.

• When a neuron dies, the nervous system promotes

recovery by altering specific synapses, functionally

reorganizing the CNS, and changing neurotransmitter

release in response to neural activity.

Cellular recovery from injury

• Injuries that damage or sever axons cause degeneration

but may not result in cell death.

Cellular recovery from injury

• Some neurons have the ability to regenerate the axon.

Cellular recovery from injury

• In contrast to injury to the axon, injuries that destroy the

cell body of a neuron invariably lead to death of the cell.

Cellular recovery from injury

• When a neuron dies, the nervous system promotes recovery by altering specific synapses, functionally reorganizing the CNS, and changing neurotransmitter release in response to neural activity.

Cellular recovery from injury

• Formation of new neurons, nerve cells,

• Stem cells in the adult human brain are capable of creating

new neurons

• Neural precursor cells migrate toward the ischemic area

following stroke.

• Researchers are still intently examining how and why

neurogenesis occurs, what drives neural precursor cells to their

target location, how to create a conducive environment for

them to survive once they reach their target

Neurogenesis

• Formation of new neurons, nerve cells,

Neurogenesis

• Stem cells in the adult human brain are capable of creating

new neurons

Neurogenesis

• Neural precursor cells migrate toward the ischemic area

following stroke.

Neurogenesis

• Reearchers are still intently examining how and why

_____ occurs, what drives neural precursor cells to their

target location, how to create a conducive environment for

them to survive once they reach their target

Neurogenesis