Lecture 12, Oct 28th

Brain Wiring

Brain Wiring

The complex arrangements and connections of neurons within the brain. Study has only been achieved in last 20-30 years due to new tech and research. much practice and knowledge is due to gunshot wounds from veterans.

Connectomics

Goal: produce simplified maps of neural connections in the brain to understand its structure and function. Multiple levels for diagrams such as Macroscopic, Mesoscopic, and Nanoscopic. classifies neurons in terms of connectivity to each other.

Neuroplasticity

The ability of the brain to reorganize itself by forming new neural connections.

Neuronal Tracts

Bundles of myelinated axons that transmit information across various regions of the brain.

Synaptic Scale

The scale at which neurophysiologic processes occur at the synapse level.

Microcircuit Scale

The scale involving small circuits of neurons interconnected for specific functions.

Systems Scale

The scale associated with large brain structures and networks.

Projection Tract

Tracts that connect higher brain regions with lower centers and spinal cord.

Association Fiber

Fibers that connect different regions within the same hemisphere of the brain.

Commissural Fiber

Fibers that cross between the left and right hemispheres of the brain.

Diffusion Tensor Imaging (DTI)

An imaging method used to study white matter tracts in the brain.

Fractional Anisotropy (FA)

A measure used in DTI to calculate the directionality of water diffusion in neural fibers.

Superior Longitudinal Fasciculus (SLF)

A bundle of axons connecting different regions of the ipsilateral cortex.

Arcuate Fasciculus (AF)

A tract connecting language comprehension and production areas in the brain.

Long Association Fibers

Fibers that connect different lobes of a hemisphere to each other.

Short Association Fibers

Fibers that connect different gyri within a single lobe.

Histology

The study of the microscopic structure of tissues.

Fluorescent Dyes

Dyes used to stain neural tissue for visualization under ultraviolet light.

Electrophoresis

A technique used to separate DNA, RNA, or proteins based on size and charge.

Degenerative Axonal Tracing

Methods to trace the pathways of axons using substances like horseradish peroxidase.

Automated Axonal Tracing

A technique using technology to create 3D models of neuronal pathways.

Connectome

The comprehensive map of neural connections in the brain.

Cerebral Cortex

The outer layer of the brain involved in complex functions like perception and memory.

Myelination

The process of forming a myelin sheath around a nerve to improve signal transmission.

Long-Range Tractography

The mapping of long-distance neural tracts within the brain.

U-Shaped Fibers

Fibers that connect different parts of the brain, notably between hemispheres.

Neuroanatomy

The study of the structure of the nervous system.

Visual Contrast

The difference in visual properties that makes an object distinguishable.

Acquisition Time

The duration required to obtain images or data from a specific technique.

Cingulum Bundle

A major white matter tract that encircles the corpus callosum.

Cortico-Cortical Pathways

Connections that link different areas of the cortex.

Hebbian Plasticity

The principle that neurons that fire together wire together, enhancing synaptic strength.

Longitudinal Tracts

White matter pathways that run along the length of the brain.

Parceling of the Cortex

Dividing the brain cortex into distinct regions for specific functions.

Neurophysiologic Processes

Processes involving the function and communication of neurons.

Somatosensory Information

Sensory data that comes from the physical body, including touch and proprioception.

Brodmann Areas (BA)

Regions of the brain defined based on their cytoarchitecture.

Synaptic Pruning

The process of eliminating excess neurons and synapses.

Information Transfer

The process of relaying information between different brain regions.

Corpus Callosum

The largest commissural fiber tract connecting the left and right cerebral hemispheres.

Wernicke's Area

Region of the brain associated with language comprehension.

Broca's Area

Region of the brain associated with speech production.

Neural Circuitry

The interconnected pathways and networks formed by neurons.