NEUROBIOLOGICAL BASIS
OF PSYCHOLOGY
Neurobiological Psychology
➢ A scientific field of behavioral
neuroscience.
➢ Behavior is not only governed by
psychosocial factors alone but also by
biological process.
Nervous System
➢ The Neuron – Basic structural unit.
➢ Cell body (soma) – Nucleus is centrally
located and is center of nourishment.
➢ Axon – Conducts nerve impulses away
from the cell body (sender).
➢ Dendrite – Conducts neutral impulses
towards the cell body (receiver).
Functions of Neurons
1. Sensory Neurons (Afferent Neurons)
➢ Sends impulses from the receptors to the
brain.
2. Interneuron
➢ Conducts neural impulses from sensory
neuron to a motor nerve cell.
3. Motor (Efferent Neuron)
➢ Sends impulses from the brain to a motor
nerve cell.
Glial cells – non-neural cells which provide the
supportive framework of the nervous system.
Neurotransmitters
➢ At the endings if each neuron are
synaptic terminals; the gap between
neurons is called synaptic gap.
➢ The junction where synaptic terminals
meet is called synapses.
➢ Each synaptic terminal contains
neurotransmitters.
➢ Chemical substances that carry messages
across the synapse either to excite other
neurons or to inhibit their firing.
Acetylcholine
➢ Facilitates learning and memory.
➢ Controls muscle contractions.
➢ Deficiency
i. Disrupts learning and memory.
ii. Alzheimer’s disease
Norepinephrine
➢ As a stress hormone, it affects part of the
human brain where attention and
responding actions are controlled. Along
with epinephrine, norepinephrine
underlies the fight-or-fight response,
directly increasing heart rate, triggering
the release of glucose from energy stores,
and increasing skeletal muscle readiness.
➢ Too little may lead to depression.
➢ Too much may cause hyperactivity.
Dopamine
➢ Major group-involved in the control of
large muscle movements and ability to
perceive pleasure.
➢ Oversupply leads to schizophrenic
reactions (delusions and hallucinations)
➢ Undersupply leads to Parkinson’s
disease.
Serotonin
➢ Involved in mood, sleep, eating.
➢ Lack produces insomnia, eating
disorders.
➢ Prevents dreaming in the waking state.
➢ Considered as the worry chemical in the
brain.
Gamma Aminobutyric Acid
➢ GABA for short.
➢ Decrease the activity of the neuron.
➢ May decrease levels of anxiety.
➢ Valium and other anti-anxiety drugs
increase the inhibiting effects of GABA.
