History and Structure of the Brain Study

History of Brain Research

• Luigi Galvani showed that stimulating a nerve of a dissected frog caused muscle movement
• Ramón y Cajal and Camillo Golgi received the Nobel Prize for their work on the nervous system
• Otto Loewi and Henry Hallett Dale discovered chemical neurotransmission
• Hans Berger developed electroencephalography (EEG) to measure electrical potentials from a living brain
• Photon Emission Tomography (PET) and functional magnetic resonance imaging (fMRI) were developed in the 1980s and 1990s respectively
• Broca and Wernicke studied the consequences of brain lesions

Brain Facts

• Brain weighs around 1200-1400g
• Brain contains 10^11 neurons
• Brain has around 10^14 - 10^15 synapses
• Glial cells are 10-50 times more numerous than neurons
• Brain is composed of 78% water, 10% lipids, and 8% proteins

Brain Structure

• The brain's structure includes the cortex, cerebellum, brainstem, and spinal cord
• The cortex is divided into allocortex (3 layers) and neocortex (6 layers)
• The cerebellum has three layers: molecular, Purkinje, and granular
• The brainstem is crucial for basic life functions like breathing, heart rate, and sleep-wake cycles

Neuronal Types

• Different neurons use specific neurotransmitters:
  • Acetylcholine (ACH): found in the brainstem, formatio reticularis (FR), striate cortex, septal cortex, basal forebrain
  • Dopamine: found in the substantia nigra, hypothalamus, olfactory bulb, and FR
  • Serotonin: found in the FR (e.g., Raphé)
  • Glutamate, Aspartate: found in the olive complex, thalamus, cerebellar cortex, neocortex, pons nuclei
  • GABA: found in the thalamus, cerebellar cortex (except granular cells), hippocampus, striate cortex, hypothalamus, and basal forebrain

Brain Function

• The brain's functional networks include the motor system, sensory system, visual system, and emotional system
• The motor system includes the primary motor cortex (M1), supplementary motor cortex (SMA), premotor cortex (PMA), and posterior parietal cortex
• The sensory system is responsible for processing sensory information
• The visual system processes visual information and consists of the dorsal pathway (where/how) and the ventral pathway (what)
• The emotional system is connected to the limbic system, which includes the hippocampus, gyrus cinguli, gyrus parahippocampalis, amygdala, limbic frontal regions, limbic areas in the diencephalon, and limbic midbrain

Brain Plasticity

• The brain is very plastic in children, enabling recovery from brain damage
• The brain's plasticity decreases with age making it more difficult to recover from brain damage later in life

Phrenology

• Phrenology, developed by Gall in 1812, is a pseudoscience that studied skull bumps to understand personality and mental abilities
• Phrenology is not a valid method for understanding brain function

Brain Structure and Function

• Brodmann's areas are regions of the cerebral cortex based on cytoarchitecture
• The motor homunculus represents the relative distribution of motor cortex devoted to different body parts
• The sensory homunculus represents the relative distribution of sensory cortex devoted to different body parts

Explore the fascinating history and facts about brain research through this quiz. Discover key figures like Galvani and Cajal, learn about the brain's structure, and understand its composition. Test your knowledge on the major advancements in neuroscience.