Neuroscience Research Methods, Genetics, and Sensory Physiology

Flashcards covering research methods in animal models, neurohistology techniques, physiological recording, brain scanning, genetics, evolution, vision, olfaction, and gustation.

What is the General Process Approach in comparative psychology?

A lens in which data and conclusions brought about by animal research are applied to the human body and physiology, based on the principle that fundamental biological, genetic, and learning processes are shared between species.

What are microelectrodes and how are they used in neural recording?

Microelectrodes are ultra-fine conductors inserted directly into brain tissue that record or stimulate individual neuron electrical activity with millisecond precision to determine function by observing tied behaviors.

What is the purpose of surgically implanting cannulas into brain structures?

Cannulas are small, hollow guide tubes that allow precise, localized delivery of drugs or chemical agents into targeted brain structures.

How does microdialysis measure chemical activity in the brain?

Microdialysis is a sampling technique using a semipermeable membrane tube inserted into brain tissue to capture and measure neurotransmitter concentrations in extracellular fluid.

What role does a sham control procedure play in stereotaxic surgery experiments?

It is a fake surgical intervention where the animal undergoes all steps of the procedure except the actual lesioning or drug delivery, serving as a baseline control to account for surgical trauma.

How was a microtome used in the historical case study of Henry Molaison (H.M.)?

H.M.'s brain was sectioned into 2,401 ultra-thin slices on a microtome to create a public 3D digital atlas mapping his precise surgical brain damage.

How did Santiago Ramón y Cajal use the Golgi staining method to establish the Neuron Doctrine?

He used Golgi staining (a silver-nitrate technique that randomly fills a small percentage of neurons completely) to prove that the nervous system is composed of discrete, individual cells rather than a continuous web.

What cellular structures are visualised using Nissl staining?

Nissl staining uses basic dyes such as cresyl violet that bind to RNA and DNA to highlight cell bodies and structural layers of brain regions without showing axons or dendrites.

What is the Brainbow technique in neurohistology?

A genetic labeling technique that forces individual neighboring neurons to randomly express distinct ratios of fluorescent proteins, showing them in a rainbow of colors.

What is NeuN and how is it utilized in immunostaining?

NeuN (Neuronal Nuclei) is a protein biomarker present in the nuclei of almost all mature neurons that is tagged by antibodies to selectively identify and count neuronal cell bodies.

What do high and low Heart Rate Variability (HRV) measurements indicate?

High HRV indicates strong parasympathetic vagal tone and stress resilience, whereas low HRV indicates sympathetic dominance or psychological stress.

How does Diffusion Tensor Imaging (DTI) visualize white matter pathways?

DTI is a variant of MRI that measures the direction and movement of water within the brain to reveal bundles of myelinated axons, wiping away grey matter in the final image.

Why does Magnetoencephalography (MEG) offer superior spatial localization compared to EEG?

MEG uses SQUIDs (Superconducting Quantum Interference Devices) to measure weak magnetic fields produced by synchronous electrical currents; magnetic fields pass through the skull bone and scalp without distortion.

What is the Blood-Oxygen-Level-Dependent (BOLD) signal in fMRI and what is its temporal limitation?

The BOLD signal measures changes in blood-oxygen levels in active brain regions, but it has a delay of about 5–10 seconds, making it a circumstantial form of evidence for brain activity.

What is a voxel in neuroimaging?

A voxel is the smallest 3D unit of measurement in a digital grid used to construct 3D images.

How do Transcranial Magnetic Stimulation (TMS) and Deep Brain Stimulation (DBS) differ in methodology?

TMS non-invasively creates a magnetic field on cortical neurons to stimulate or inhibit activity (used for depression), whereas DBS is an invasive procedure involving permanent electrode implantation into the brain.

How does Phenylketonuria (PKU) demonstrate an interaction between nature and nurture?

PKU is a genetic disorder where the body fails to break down phenylalanine, causing it to build up in the brain; environmental intervention ("nurture") via a controlled diet is required to manage the disease.

What is the difference between transgenic organisms and knockout mice?

Transgenic organisms contain foreign genetic material imported from a completely different species, whereas knockout mice use gene targeting to delete or disrupt a specific functional gene to observe physical or behavioral deficits.

What is optogenetics?

A technique combining genetic engineering and optics to control the activity of specific, targeted neurons in living tissue using light.

How do Monozygotic (MZ) and Dizygotic (DZ) twins differ genetically?

Monozygotic twins develop from a single fertilized egg that splits early in development (sharing 100% of genes), whereas Dizygotic twins develop from two separate sperm cells and eggs (sharing ~50% of segregating genes).

What is Functionalism and who pioneered this theoretical framework?

Pioneered by William James, Functionalism stems from evolutionary theory and poses that mental processes and behaviors must be understood in terms of their adaptive biological functions.

How do positive eugenics and negative eugenics differ?

Positive eugenics encourages individuals with desirable traits to reproduce, while negative eugenics uses political and social efforts (such as forced sterilization or institutionalization) to reduce traits deemed inferior.

What is sensory transduction?

The process of translating environmental or physical energy into electrical neural signals so the nervous system can interpret it.

What optical defects cause Myopia and Hyperopia?

Myopia (nearsightedness) occurs when incoming light focuses in front of the retina, blurring distant objects; Hyperopia (farsightedness) occurs when light focuses behind the retina because the eyeball is too short or the cornea lacks curvature, blurring close objects.

How do Rods and Cones differ in function and photopigment regeneration?

Rods enable scotopic (night) vision via rhodopsin, which takes 30–45 minutes to recover after light depletion; Cones enable photopic (daytime/color) vision via photopsin, which replenishes rapidly.

What are the two major theories of color perception?

Trichromatic Theory (differentiates short, medium, and long light wavelengths for blue, green, and red) and Opponent-Process Theory (organizes ganglion cells into opponent pairs: red/green and yellow/blue).

What is the complete anatomical pathway for visual information from the retina to the cortex?

Retina → Optic Nerve → Optic Chiasm → Thalamus (LGN) → Primary Visual Cortex (V1) → Visual Association Cortex (V2–V8).

What visual features are processed by the Magnocellular, Parvocellular, and Koniocellular layers of the LGN?

Magnocellular layers process form, shape, and movement; Parvocellular layers process color and fine details (spatial orientation); Koniocellular layers transmit information regarding blue light.

What functions are carried out by the Dorsal and Ventral visual streams?

The Dorsal ("Where?") stream flows to the posterior parietal lobe for spatial navigation; the Ventral ("What?") stream flows to the temporal lobe for object recognition.

What is Prosopagnosia and what brain structure is associated with it?

Prosopagnosia is face blindness (inability to recognize faces), caused by damage to the Fusiform Face Area (FFA).

What makes the primary olfactory pathway unique compared to all other sensory modalities?

Olfaction is the only sensory modality whose neural information reaches the primary olfactory cortex without first passing through the thalamus.

What structures comprise the Primary Gustatory Cortex, and how is flavor produced?

The Primary Gustatory Cortex consists of the Insula and Frontoparietal Operculum; Flavor is produced by combining Gustation (taste) and Olfaction (smell).