Neuroscience Fundamentals

Neurons

• Basic building blocks of the nervous system
• Consist of:
  • Dendrites: receive signals
  • Cell body: contains nucleus and maintains cell function
  • Axon: transmits signals
• Types of neurons:
  • Sensory neurons: transmit signals from sensory receptors to CNS
  • Motor neurons: transmit signals from CNS to muscles or glands
  • Interneurons: integrate and process information within CNS

Synapses

• Small gaps between neurons that allow chemical communication
• Process:
  1. Neurotransmitter release from axon terminal
  2. Binding of neurotransmitter to receptors on postsynaptic neuron
  3. Signal transmission and integration
• Types of synapses:
  • Excitatory: increase likelihood of action potential
  • Inhibitory: decrease likelihood of action potential
  • Electrical: direct electrical connection between neurons

Brain Anatomy

• Cerebrum: largest part of brain, divided into:
  • Cerebral cortex: outer layer, responsible for sensory perception, thought, and voluntary movement
  • Basal ganglia: involved in movement control and cognition
  • Hippocampus: plays key role in memory formation
• Cerebellum: coordinates muscle movements and balance
• Brainstem: connects cerebrum to spinal cord, regulates basic functions (breathing, heart rate, etc.)

Nerve Conduction

• Mechanism by which neurons transmit information
• Action potential:
  • Depolarization: rapid change in membrane potential
  • Repolarization: return to resting state
• Saltatory conduction: rapid transmission of action potential between nodes of Ranvier
• Myelination: insulation of axons by Schwann cells, increases conduction speed

Sensory Processing

• Conversion of external stimuli into neural signals
• Process:
  1. Transduction: conversion of stimulus into electrical signal
  2. Transmission: signal transmission to CNS
  3. Perception: interpretation of signal by brain
• Types of sensory receptors:
  • Mechanoreceptors: respond to touch, pressure, and vibration
  • Photoreceptors: respond to light (vision)
  • Chemoreceptors: respond to chemicals (taste, smell)
  • Thermoreceptors: respond to temperature