Neuroscience Fundamentals

Deconstructing Neuromyths

• The "10% brain usage" myth is false; all brain areas are active at different times.
• Hemispheric specialization is true for only a few lateralized activities.

Key Numbers and Concepts

• The approximate weight of the human brain is 1.3-1.5 kg.
• The brain consumes 20-25% of the body's energy.

Neuroanatomy

• The cerebral cortex is divided into 6 layers.
• The Pia mater is the layer of the meninges closest to the brain.

Electrophysiology

• The myelin sheath insulates the axon, allowing for faster signal transmission.
• Sodium (Na+) is the primary ion responsible for depolarizing the neuron during an action potential.

Plasticity

• Brain plasticity refers to the brain's ability to reorganize and form new neural connections.

Neurogenesis

• In adult humans, neurogenesis primarily occurs in the subventricular zone and dentate gyrus.

Glial Cells

• Oligodendrocytes form the myelin sheath in the central nervous system.
• Microglia are primarily involved in phagocytosis of cellular debris.

Brain Imaging

• MRI is commonly used for functional imaging of the brain.
• PET scans are useful for imaging tumors and neurodegenerative diseases.

Neurodegenerative Diseases

• Huntington's disease is primarily caused by an expansion of CAG repeats in the HTT gene.
• Parkinson's disease is characterized by the loss of dopaminergic neurons in the substantia nigra.

Therapeutic Approaches

• Gene therapy involves editing the genetic code, inhibiting gene expression, and administering small molecules.
• Antisense oligonucleotides (ASO) are used to reduce the expression of mutant alleles.

Additional Notes

• The Mozart effect has no significant effect on intelligence.
• The concept of learning while sleeping is a myth.
• The Encephalization Quotient (EQ) for humans is approximately 7.5.
• Astrocytes can dedifferentiate into neural stem cells.
• Ependymocytes are responsible for producing cerebrospinal fluid (CSF).
• Microglia change morphology based on the presence of pathogens and their function.
• The spatial resolution of a CT scan is approximately 0.5 x 0.5 mm.
• Ultrasound uses sound waves for imaging.
• A common non-motor symptom of Parkinson's disease is depression.
• The most common form of Alzheimer's disease is the sporadic form.
• Lecanemab (LEQEMBI) is used to treat Alzheimer's disease.
• CRISPR-Cas9 is a technology used for targeted genetic modification.
• Lewy bodies in Parkinson's disease contain aggregates of α-synuclein.
• A common environmental factor linked to Parkinson's disease is neurotoxins like Rotenone.
• Microglia are the primary immune cells of the central nervous system.
• In Alzheimer's disease, microglia are often found near amyloid plaques.
• Neurofibrillary tangles in Alzheimer's disease are composed of Tau protein.
• One of the early diagnostic tools for Alzheimer's disease is MMSE scoring.
• The blood-brain barrier (BBB) is primarily maintained by astrocytes.
• The primary function of Schwann cells is to form myelin sheaths in the peripheral nervous system.