Intro to Biopsychology

Introduction to Biopsychology

• The brain consumes 25% of the body's energy despite only making up 2% of its weight.
• The brain communicates through neurons using electrical and chemical signals, with an infinite number of possible signal paths.
• Neuroscience is the scientific study of the nervous system, and biopsychology is a field that focuses on how the brain generates behavior and cognitive functions.

The Brain and Behavior

• Psychology is the scientific study of behavior, while bio refers to the scientific study of biology.
• Biopsychology is a rapidly growing field that combines these two disciplines to study the biology of behavior.
• Dr. D.O. Hebb's work, "The Organization of Behaviour" (1949), was influential in establishing biopsychology as an integrative discipline.
• Biopsychology considers various subfields, including neuropharmacology, neuropathology, neurochemistry, neurophysiology, neuroanatomy, and neuroendocrinology.

Divisions of Biopsychology

• Physiological psychology
• Psychopharmacology
• Neuropsychology
• Psychophysiology
• Cognitive neuroscience
• Comparative psychology

Divisions of the Nervous System

• Central nervous system (CNS): brain and spinal cord, housed in protective bony structures
• Peripheral nervous system (PNS): outside the cranium and vertebrae column
  • Somatic nervous system: interacts with external environment
    • Afferent nerves: bring in sensory information from outside to the CNS
    • Efferent nerves: take out signals from the CNS to the external environment
  • Autonomic nervous system: interacts with internal environment, regulates body internally
    • Afferent nerves: bring in signals from internal organs to the CNS
    • Efferent nerves: take out signals from the CNS to internal organs

Neurons and Glial Cells

• Neurons: cells of the nervous system, with a membrane and embedded proteins
• External features of neurons:
  • Dendrites: receive signals from other cells
  • Axon: carries signals to the end of the neuron
  • Synaptic vesicles: contain neurotransmitters
• Internal features of neurons:
  • Nucleus: contains genetic material
  • Mitochondria: site of aerobic energy release
  • Rough endoplasmic reticulum: site of protein synthesis
  • Fluid endoplasmic reticulum: site of fat synthesis
  • Cytoplasm: internal environment of the cell
• Glial cells:
  • Oligodendrocytes: CNS only, myelinate axons
  • Schwann cells: PNS only, myelinate axons
  • Microglial cells: respond to injury or disease
  • Astrocytes: largest glial cells, cover blood vessels that supply the CNS

Neocortex Organization

• Different types of cells located in the layers of the neocortex
  • Parametal cells: multipolar neurons with a parameter shape
  • Stellate cells: shaped like stars, short axons, mainly interneurons
• Differences in the layers of the cerebral cortex
  • Size of cell bodies
  • Density of cell bodies
  • Relative proportions of parametal and stellate cells
• Columnar organization of the neocortex
  • Vertical connections across layers due to dendrites of parametal cells
  • Neurons in a given column form a mini-circuit
• Thickness of the different layers may vary

Old Cortex Structure

• Hippocampus: located on the medial edge of the cerebral cortex, has 3 layers, and is involved in memory function
• Wrinkled structure: cerebral cortex has folds, increasing cortical area without increasing the size of the cranium

Explore the basics of biopsychology, including the brain's energy consumption, neural communication, and the study of neuroscience and its relation to behavior and cognitive functions.