Cognitive Neuroscience Exam 2

Psychopharmacology:

study of how drugs affect the nervous system and behavior.

Psychoactive drug:

alters mood, thought, or behavior. (used to manage neuropsychological illness)

Agonist:

enhances synaptic function.

Antagonist:

blocks or decreases synaptic function.

Oral:

most common, many barriers before reaching brain. (easy and convenient. safest?)

Inhalation:

faster absorption, fewer barriers.

Skin/mucous membranes (patches):

steady absorption.

Injection:

• Intravenous (IV): bloodstream, very fast.

• Intramuscular (IM): slower release.

• Intracranial: directly into brain, highest risk.

Intravenous (IV):

bloodstream, very fast.

Intramuscular (IM):

slower release.

Intracranial:

directly into brain, highest risk

Rule of 10:

each barrier eliminated allows 10x lower dose but increases overdose risk.

Blood–Brain Barrier

• Tight endothelial cells in brain capillaries.

• Barrier-free sites: pituitary gland, pineal gland, area postrema.

• Transport: small lipid-soluble molecules cross easily, large molecules require active transport.

(TBT)

Barrier-free sites: pituitary gland, pineal gland, area postrema.

• Pituitary: target for blood borne hormones

• Pineal: target for hormones that affect circadian rhythms (pinwheel)

• Area postrema: detects and initiates vomiting of noxious substances (extrema)

Drug Elimination

• Catabolism: liver (cytochrome P450 enzymes), kidneys, intestines. LIK

• Excretion: urine, feces, sweat, breast milk, exhalation. bfuse

• Risk of toxicity if substances accumulate.

Catabolism:

liver (cytochrome P450 enzymes), kidneys, intestines.

Excretion:

urine, feces, sweat, breast milk, exhalation.

Drug Action at Synapses

Sites of action: synthesis, storage, release, receptor binding, inactivation (reuptake or enzymes). SSRRI

Tolerance:

decreased response with repeated use.

Metabolic tolerance:

more enzymes produced.

Cellular tolerance:

neurons adapt.

Learned tolerance:

behavioral compensation.

Sensitization:

increased responsiveness, often with intermittent use. (Because body recognizes and reacts to the drug faster)

Adenosinergic:

caffeine.

Cholinergic:

nicotine.

GABAergic:

alcohol, benzodiazepines.

Glutamatergic:

PCP, ketamine.

Dopaminergic:

Cocaine, Amphetamines, Ritalin, Antipsychotics. CARA

Serotonergic:

SSRIs, psychedelics.

Opioidergic:

Morphine, Heroin, Fentanyl. HMF

Cannabinergic:

THC, CBD.

ADHD:

dopamine/norepinephrine dysfunction; stimulant treatment.

Schizophrenia:

dopamine hypothesis; D2 antagonists. (Imbalance of dopamine is responsible for Schizophrenia. Use a D2 antagonist medication for schizophrenia)

Depression:

SSRIs, CBT, ketamine, ECT.

Fetal Alcohol Spectrum Disorder:

developmental impairments from prenatal alcohol exposure.

Broca:

left frontal lobe damage caused speech production deficits.

Brodmann:

cortical mapping based on cytoarchitecture.

Human testing:

memory, attention, perception tasks. MAP

• Animal models:

• Morris water maze (spatial memory).

• Skilled reaching task (motor control).

• Touchscreen tasks (cognitive testing in rodents).

Lesions:

ablation, stereotaxic surgery, high-intensity ultrasound. ASH

Compensation:

plasticity after damage.

Electrical stimulation:

Penfield mapping, self-stimulation.

Deep Brain Stimulation:

used for Parkinson’s, OCD, epilepsy.

Transcranial Magnetic Stimulation:

non-invasive stimulation for depression.

Drug manipulations:

targeted injections.

CRISPR-Cas9:

gene editing.

Optogenetics:

light-sensitive ion channels to control neurons.

Chemogenetics (DREADDs):

receptors activated only by designer drugs.

GRAB technology:

fluorescent neurotransmitter sensors.

Brain organoids:

lab-grown brain tissue models.

Anatomical:

CT, MRI, DTI, MRS

Functional:

fMRI, PET.

Electrical:

EEG, ERP, MEG.

Prenatal Development

• Zygote (0–2 weeks) → Embryo (2–8 weeks) → Fetus (9 weeks–birth).

• Neural plate folds into neural tube around 3 weeks.

• Key events:

  • Day 49: embryo resembles miniature human.

  • Day 60: sexual differentiation.

  • Seven months: gyri and sulci form.

  • Nine months: adult-like brain.

Day 49:

embryo resembles miniature human.

Day 60:

sexual differentiation.

Seven months:

gyri and sulci form.

Nine months:

adult-like brain.

Neural Development Processes

1. Cell birth (neurogenesis, gliogenesis).

2. Cell migration (guided by radial glia).

3. Differentiation into neurons and glia.

4. Maturation: dendritic arborization, axon growth.

5. Synaptogenesis: rapid increase after birth.

6. Apoptosis and pruning: experience-dependent removal of excess cells.

7. Myelination: continues into early adulthood.

8. Adult neurogenesis: debated, mostly hippocampus and subventricular zone.

Cell birth

(neurogenesis, gliogenesis).

Cell migration

(guided by radial glia).

Differentiation

into neurons and glia

Maturation:

dendritic arborization, axon growth.

Synaptogenesis:

rapid increase after birth.

Apoptosis and pruning:

experience-dependent removal of excess cells.

Myelination:

continues into early adulthood.

Adult neurogenesis:

debated, mostly hippocampus and subventricular zone

Influences

• Genes, hormones, sensory experience, stress, SES.

• Hebb: enriched environments increase synapses and astrocytes.

Cognitive Development

• Motor milestones: correlate with myelination of motor cortex.

• Language development: Broca’s area connectivity increases around 2 years.

• Piaget’s stages: sensorimotor, preoperational, concrete, formal operations.

• Brain growth spurts align with Piaget stages.

Motor milestones:

correlate with myelination of motor cortex.

Language development:

Broca’s area connectivity increases around 2 years.

Piaget’s stages:

sensorimotor, preoperational, concrete, formal operations

Autism spectrum disorder:

atypical connectivity, variable severity.

Adverse Childhood Experiences:

lasting effects on frontal lobe development.

Sensation:

registration of physical stimuli.

Perception:

subjective interpretation of sensory input.

Illusions

show that perception is a construction of the brain.

Cornea:

outer covering, bends light.

Iris and pupil:

regulate light entry.

Lens:

focuses light.

Retina:

rods for dim light, cones for color and acuity.

Fovea:

central, high-acuity vision.

Blind spot:

optic disc with no receptors.

Optic chiasm:

nasal fibers cross to opposite hemisphere.

Geniculostriate system:

retina → LGN → V1.

Tectopulvinar system:

retina → superior colliculus → pulvinar → visual areas.

Retinohypothalamic tract:

regulates circadian rhythms.

Ventral stream (“what”):

temporal lobe, object identification.

Dorsal stream (“how/where”):

parietal lobe, spatial action.

Migraines:

aura caused by vessel dilation.

Blindsight:

unconscious vision due to cortical damage.

Fusiform face area damage:

prosopagnosia (face blindness).

Glaucoma:

optic nerve damage causing vision loss.

Frequency (Hz):

pitch.

Amplitude (dB):

loudness.

Complexity:

timbre.

Speech

is largely processed in the left hemisphere.

Music

is largely processed in the right hemisphere.

Outer ear:

pinna, ear canal.

Middle ear:

ossicles (hammer, anvil, stirrup).