Biological Basis for Understanding Psychiatric Disorders and Treatments
 Describe the anatomy and physiology of the brain structures.
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Describe the function of each of the major neurotransmitters affected by psychotropic medications.
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Discuss the purpose of imaging of the brain.
Functions and Activities of the Brain
 Maintain homeostasis
 Regulation of autonomic nervous system (ANS) and hormones
 Control biological drives and behaviors
 Circadian rhythms: cycle of sleep/wakefulness
 Conscious mental activity
 Memory
 Social skills
Cellular Composition of the Brain
 Neurons
Respond to stimuli
 Conduct electrical impulses
Release chemicals/neurotransmitters
Has 3 types of actions
 Response to stimuli
 Conduction of electrical impulses
 Release of neurotransmitters
Neuronal Action
  Neurons can release more than one chemical at the same time.
  Neuropeptides-Long-term changes in postsynaptic cells, may affect stimuli responsiveness
  Neurotrophic factors-influence growth, shape, most acute during fetal development, but is retained
through life
 Proteins and Gases (carbon monoxide, nitrous oxide)
  Effect of steroid hormones (estrogen, testosterone, cortisol)
 Steroid psychosis
Anatomical plasticity
  Neuroplasticity is the changing of the structure, function and organization of neurons, or nerve cells,
in response to new experiences.
  Altered genetic expression or environmental trauma can change this and result in negative or positive
consequences
Brainstem
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Core
 regulates internal organs
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Hypothalamus
 Basic drives
 Link between thought and emotion
 Function of internal organs
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Brainstem
 Processing center for sensory information
Cerebellum
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“little brain”
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Motor control: puts the “polish” on the movements
Skeletal muscle coordination and contraction
 Equilibrium
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Some involvement in learning, attention & language
Cerebrum
 Largest part of the brain
 Movement of skeletal muscles
Language and communication
Sensory processing
Conscious sense of being
Learning and memory
 This part of the brain governs executive functioning (frontal lobe).
The Limbic System
 A group of brain structures that govern emotions and behaviors.
Connected to brain’s pleasure center (DA)
 Epinephrine flow
 Emotion
 Behavior
 Motivation
 Long-term memory  Olfaction
NEUROTRANSMITTERS
Understanding the actions of neurotransmitters helps a nurse understand if a medication is effective and/or the
side effects the patient may be experiencing. It helps us personalize nursing interventions and teaching.
Measuring...
 As current science stands, there is no way to measure neurotransmitters.
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Diagnoses are based on behaviors, patterns of symptoms, and ability to function through careful
histories and observations.
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The future is working on this testing.
(For example, Serotonin is usually measured post-mortem.)
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Dopamine (DA)
 Involved in fine motor movements
 Decision making & reward-motivated behaviors
 Has functions outside the CNS, “paracrine” function.
 Decrease: Parkinson’s, depression, ADHD, RLS
 Increase: Psychosis, mania
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Norepinephrine (NE)
 Can act as both a neurotransmitter & a hormone
 Mood
 Attention and arousal
 “fight or flight” response from sympathetic branch of autonomic nervous system
 Decrease: Depression
 Increase: Anxiety, mania, schizophrenia
Serotonin (5-HT)
  Hunger, pain, mood, sleep regulation.
  Plays a role in aggression and sexual behavior.
  Influences some cognitive functions, i.e. learning and memory.
  Decrease: Depression
  Increase: Anxiety
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Histamine (H)
 Alertness, sleep/wake cycle  Learning and memory
 Inflammatory response
 Decrease: Sedation, weight gain, anticholinergic effects.
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Glutamate
Works on NMDA and AMPA receptors
  NDMA
 Decrease: psychosis
 Increase: Alzheimer’s neurodegeneration, injury (toxic)
  AMPA
 An increase improves cognitive performance and behavioral tasks.
Gamma-Aminobutyric Acid (GABA)

Chief inhibitory neurotransmitter
 Inhibition
Perception of pain
Reduction of aggression, anxiety
Anticonvulsant and muscle relaxant properties
May impair cognition and psychomotor functioning.
Acetylcholine (Ach)
 Role in learning and memory
 Mood regulation
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Affects sexual and aggressive behaviors
 Stimulates the parasympathetic nervous system: SLUDD
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Decrease: Alzheimer's, Huntington’s, Parkinson’s
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Increase: depression
Neuromodulators: Peptides
 Substances that are released by a neuron & transmits information to other neurons which alters
their activity
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Substance P (SP)
 Enhances sensitivity to pain
 Regulation of mood & anxiety
 Promotes & reinforces memory
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Somatostatin (SRIF)
 Altered levels are associated with cognitive disease
Neurotensin (NT)
 Antipsychotic-like properties
Visualizing the Brain
 Electroencephalograph (EEG)
 Structural imaging
 Computerized axial tomography (CT
 Magnetic resonance imaging (MRI)
 Functional magnetic resonance imaging (FMRI)
 Functional imaging
 Positron emission tomography (PET)
 Single photon emission computed tomography (SPECT)
Disturbances of Function
 Causative factors are not yet understood.
 Environment
 Genetics
 Trauma
 Altered neurons
 Norepinephrine (NE)
 Serotonin (S)
 Dopamine (DA)
 Glutamate
 g-aminobutyric acid (GABA)