Biopsychology The Brain and Behavior
Outline Techniques to study Brain The Neuron: structure and function Organization of Nervous System Localized function Lateralized function Endocrine system Behavioral genetics
Techniques History: Hippocrates Galen Gall & Spurzheim “Phrenology in 1820’s” Gage 1848 Broca 1861: Patient Leborgne shows aphasia (no speech); Left frontal lobe damaged. Wernicke : process language in temporal lobe in left hemisphere
Surgical “ablation” after gunshots, tumors or strokes. C. Golgi “silver staining technique. S. Ramon y Cajal 1880’s used staining method to map neuron structure and gap between neurons. Penfield -1952 Hess 1955 “rats and hypothalamus control of eating” EEG
Imaging of live brain CAT- computerized axial tomography MRI – magnetic resonance imaging PET – positron emission tomography BEAM : brain electrical activity mapping MEG : magnetoencephalography PRONG: parallel recording of neural groups SPECT : single-photon emission computerized tomography; cerebral blood flow.
The Generic Neuron
The Neurons Connected
Structure of Neuron Cell body ( cyton or soma) Dendrites Axon ends in terminal buttons which have synaptic vesicles contain neurotransmitters. Myelin sheathing covered in Schwann cells segments between sheaths are nodes of Ranvier
Neurotransmitters: Acetylcholine (ACh) Amino Acids- glutamate and aspartate Gamma-aminobutyric acid (GABA) Dopamine and norepinephrine are catecholamine. Serotonin Opioid peptides – endorphins 60 others are known to function in brain alone.
Synaptic Gap
Some of 200 types of neurons
Motor neurons: message from CNS to muscles and glands. Classes of Neurons: Three types Sensory, Motor, Interneurons. Sensory neurons : messages from sense receptors to central nervous system (CNS). Motor neurons: message from CNS to muscles and glands. Interneurons :messages between neurons. GLIA cells perform housekeeping, insulation, and protection.
Neural Impulse “All-or-nothing” principle At rest more negative inside then out at -70mV. Sodium-Potassium pump Stimulated to “Threshold” net flow of Na+ out and K+ ions in. Causing +40mV action potential. Intense stimulus, frequent firing.
Action Potential
Refractory period Synapse Simplest form of behavior: Reflex arc ( knee jerk, eye blink. Graded Potentials : generated by excitatory input and vary in size. Many are needed to fire neuron. Temporal & Spatial Summation
Nervous System
Brain Anatomy The Brain Explorer Website
Split Brains
Endocrine System Endocrine vs. Nervous system Hormones Glands: Pineal Hypothalamus Pituitary Thyroid Parathyroid
Adrenal: cortex and medulla Pancreas Gonads: Ovaries and Testes
Behavioral Genetics Darwin, Evolution and Determinism (1850) Continuity between animal – humans Individual differences Adaptability Environmental pressure Change occurs
Humans Evolved Three critical changes: Phenotype vs. Genotype Encephalization Bipedal Language Phenotype vs. Genotype Genes and behavior (Dr. S. Pinker: The Blank Slate – MIT) Nature vs. Nurture Heredity vs. Environment 46 chromosomes carrying genes to build protien from DNA patterns. 1 pair XX or XY
Twin Studies Human Genome Project : 23 chromosome pairs have been mapped. Book by Dr. Ridley: Genome