Biology and Behavior

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Biology and Behavior

• Neural Control Systems
• Psychopharmacology
• The Nervous System
• How do we know these things?

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Cells and synapses

• Cells of the nervous system
• Glial cells
• Astrocytes and oligodendrocytes
• Neurons
• Unipolar, bipolar, and multipolar
• Soma, axons and dendrites
• Synapses

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Neural transmission 5 steps

• 1. Resting potential -70mV
• Pump Na out, K in
• 2. Threshold stimulation-65mV
• 3. Action potential 50mV
• Allow Na in, K out
• 4. Refractory period -80mV
• 5. Restore resting potential

mV
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Ion movements
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Ion movements
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The propagation of the action potential
Note Myelin sheath Nodes of Ranvier Saltatory
conduction
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Seven steps of synaptic transmission

• Manufacture and storage of neurotransmitter
  (acetylcholine, dopamine, norepinephrine,
  serotonin)
• Arrival of action potential
• Release of NT into synaptic cleft
• Bonding of NT with receptor sites
• Change in receiving neuron
• Release of NT back into cleft
• Metabolism or reuptake

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The Synapse
Axon terminal
Post-synaptic membrane (dendrite, muscle, gland)
Neurotransmitters
Synaptic vesicles
Receptor sites
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Some neurotransmitters

• Acetylcholine (ACh)
• Norepinephrine (NE)
• Serotonin (5-HT)
• Dopamine (DA)
• g-amino butyric acid (GABA)
• Glutamate or glutamic acid (GA)
• Endorphins and enkephalins

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The nervous system

• Two main divisions
• Central Nervous System (CNS)
• Encased in bone (skull and spinal column)
• Peripheral Nervous System

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CNS

• Two main divisions
• Brain
• Spinal cord

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PNS

• Cranial and spinal nerves
• Sensory-Motor system
• Autonomic Nervous System (ANS)
• Sympathetic Nervous System (SNS)
• Parasympathetic Nervous System (PSNS)

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The brain

• Brain stem
• Medulla Vegetative functions
• Pons Connections
• Tectum and tegmentum Reflexes
• Cerebellum Postural reflexes, movements
• Cerebral hemispheres

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Cerebral hemispheres

• Cerebral cortex Gray matter
• Frontal lobe
• Parietal lobe
• Temporal lobe
• Occipital lobe
• Sub-cortical gray-matter structures
• Limbic system
• Thalamus and hypothalamus
• Hippocampus
• White matter Communication
• Male and female general intelligence (Haier
  Jung, 2005)

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Lobes of Cortex
Parietal lobe
Central Sulcus
Occipital Lobe
Frontal lobe
Temporal Lobe
Cere- bellum
Pons
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Color-Coded Cortex
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Methods of studying the brain

• Animal models
• Stereotaxic methods
• Natural ablation studies, surgery
• Psychopharmacology
• Imaging techniques
• CT, MRI, PET scans
• Recording methods EEG

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Psychopharmacology

• Pheromones
• Hormones
• Neuromodulators
• Neurotransmitters

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Drug effects

• Hormone mimics and receptors
• Adrenaline, estradiol
• Alter manufacture or release of neurotransmitters
• Black widow venom, botulinum toxin (Botox)
• Mimic or block receptor sites
• Nicotine, curare, chlorpromazine

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Drug effects 2

• Inhibit reuptake Cocaine, fluoxetine
• Stimulate neuromodulators
• Barbiturates and benzodiazepines

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Hormones The endocrine system

• The hypothalamus and the pituitary body
• Hormone receptor molecules
• Oxytocin acts only on mammary glands and the
  uterus
• Testosterone acts on facial hair receptors

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Endocrine control

• Hypothalamus controls by releasing hormones
• CRH (Corticotropin Releasing Hormone)
• Anterior part of pituitary releases ACTH
  (Adrenocorticotropic Hormone)
• Adrenal cortex releases cortisol
• Hypothalamus detects cortisol and lowers release
  of CRH
• Other glands are controlled in similar ways.

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Other glands and hormones

• Anterior pituitary GH (Growth Hormone)
• Dwarfism and gigantism
• Thyroid Thyroxine and triiodothyronine
• Metabolic rate, growth, maturation
• Pancreas Insulin
• Pituitary LH (Luteinizing Hormone) and FSH
  (Follicle Stimulating Hormone) activate ovaries
  and testes to produce gametes and sex hormones

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The Brainstem
Thalamus
Tectum/Colluculi
Tegmentum
Pons
Medulla
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CT, PET, and MRI scans

• CT, PET and MRI scan facilities
• This clip shows the typical apparatus.
• The person lies on the bed, with the head in the
  doughnut opening.

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MRI in psychological research

• In this clip, you see the MRI results as a
  participant watches visual stimuli of two types,
  either combinations of lines or a moving figure
  with human proportions.

Note Light yellow indicates high activity.
Occipital lobe is in the center of this view of
the brain temporal to the side.