Neuroscience final

Basal Ganglia

Deep brain structures involved in motor control, learning, and regulating voluntary movement.

Corpus Striatum

Composed of the caudate nucleus and putamen; a major component of the basal ganglia.

Globus Pallidus

Part of the basal ganglia with internal and external segments, involved in regulating motor output.

Substantia Nigra

A structure of the basal ganglia that produces dopamine, critical for motor control.

Direct Pathway

Pathway that facilitates movement by promoting excitation of motor cortex.

Indirect Pathway

Pathway that inhibits movement by dampening unwanted motor programs.

Medium Spiny Neurons (MSN)

The primary neurons in the striatum, comprising 96% of its neurons, responsible for integrating cortical input.

Dopamine Receptors

Receptors on striatal neurons that mediate the effects of dopamine; include D1 (excitatory) and D2 (inhibitory) receptors.

Excitation

The activation of neural pathways that promote movement.

Inhibition

The suppression of neural activity that restricts movement.

Disinhibition

A process where inhibition is removed, allowing for increased activity in the thalamus and and promotes movement.

Afferent Pathways

Input pathways to the basal ganglia primarily from the cerebral cortex.

Corticostriatal Pathway

Pathway projecting from the cortex to the striatum, carrying excitatory glutamatergic input.

Glutamatergic Transmission

Excitatory synaptic transmission involving the neurotransmitter glutamate.

Saccades

Rapid eye movements that are controlled by projections from the substantia nigra to the superior colliculus.

Parkinson’s Disease

A neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra, leading to motor control deficits.

Synaptic Plasticity

The ability of synapses to strengthen or weaken over time, influencing learning and motor control.

Long-term Potentiation (LTP)

A long-lasting increase in synaptic strength following high-frequency stimulation.

Long-term Depression (LTD)

A long-lasting decrease in synaptic strength following low-frequency stimulation.

Broca’s Area

Region in the frontal lobe involved in language production.

Wernicke’s Area

Region in the temporal lobe associated with language comprehension.

Aphasia

A disorder characterized by impaired ability to produce or comprehend language.

Motor Cortex

Area of the brain responsible for planning and executing voluntary movements.

Cortical Association Areas

Regions of the cerebral cortex that integrate sensory and motor information, contributing to complex functions like language.

Dopaminergic System

The system in the brain that uses dopamine as its neurotransmitter, influencing both motor control and reward processing.

Subthalamic Nucleus (STN)

A component of the basal ganglia that plays a role in modulating motor activity and output pathways.

Neurotransmission

The process by which signaling molecules (neurotransmitters) transmit signals across synapses.

Tonic Inhibition

Constant suppression of neuron activity that regulates the overall excitability of neural circuits.

Excitatory Postsynaptic Potential (EPSP)

A postsynaptic potential that makes a neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A postsynaptic potential that makes a neuron less likely to fire an action potential.

Cerebral Cortex

The outer layer of the brain involved in complex functions like perception, thought, and action.

Frontal Lobe

Part of the brain responsible for higher cognitive functions, including decision making and motor control.

Parietal Lobe

Region of the brain that processes sensory information and spatial orientation.

Cortex-Striatum Connection

The pathway linking the cortex to the striatum, crucial for integrating sensory and motor information.

Thalamus

Brain structure acting as a relay station for sensory and motor signals to the cortex.

GABAergic Neurons

Inhibitory neurons that utilize gamma-aminobutyric acid (GABA) as a neurotransmitter.

Neuroplasticity

The capacity of the brain to change and adapt in response to experience.

Upper Motor Neurons (UMN)

Neurons located in the brain that send signals to lower motor neurons in the spinal cord.

Neuromodulators

Substances that influence the efficacy of synaptic transmission.

Comparative Aphasias

Classification of aphasia types based on location of brain damage and associated symptoms.

Symbolic Representation

The ability to use symbols for communication, essential in language.

Grammar

A system of rules that governs how symbols are used in language.

Syntax

The arrangement of words and phrases to create well-formed sentences in a language.

Prosody

The rhythm, stress, and intonation in spoken language that conveys emotional meaning.

Habit Formation

The process by which behaviors become automatic through repetition and reinforcement.

Neuromodulation

The process by which certain neurotransmitters affect the strength of synaptic transmission.

Calcium Signaling

Involves calcium ions in cellular processes, important for synaptic plasticity.

Neural Circuit Dynamics

The patterns of activity and connection among neurons that mediate processing and behavior.

Lateralization

The specialization of certain functions, such as language, in one hemisphere of the brain.

Pathway Competition

Interactions between different neural pathways that can synergistically or antagonistically influence behavior.

Dopaminergic Control

The regulatory effects of dopamine on various neural pathways associated with motor and reward processes.

Cognitive Function

The mental processes involved in gaining knowledge and comprehension.

Limbic System

Group of structures involved in emotions, memories, and arousal.

Functional Connectivity

The relationship between distinct neuronal populations and their coordinated activity.

Motor Planning

The cognitive process of preparing and organizing movements before execution.

Hemispheric Dominance

The tendency for one hemisphere of the brain to exert greater influence over certain functions.

Striatal Feedback Loop

The connection from the striatum back to the cortex that provides regulatory feedback.

Midbrain Structures

Brain components located in the midbrain region that are involved in motor control, most notably the substantia nigra.

Cerebellar Processing

The way the cerebellum integrates sensory perception and motor output to fine-tune movements.

Dopaminergic Pathways

Neural pathways that use dopamine as a neurotransmitter, influencing many brain functions.

Neurotransmitter Release

The process by which neurotransmitters are released from neurons to communicate with other neurons.

Behavioral Flexibility

The ability to adapt behavior based on changing conditions or environments.

Brainstem Nuclei

Clusters of neurons in the brainstem that are involved in regulating basic life functions and motor control.

Habitual Behaviors

Actions that are performed automatically in response to cues or contexts due to repetition and reinforcement.

Functional Reserve

The brain’s ability to compensate for potential damage or loss in specific functions.

Neural Pathway

A series of connected neurons that communicate via synapses to convey information.

Crticial Areas of Language

Brain regions primarily responsible for the processing and production of language.

Neuronal Integration

The process by which multiple synaptic inputs are combined in a neuron, influencing its output.

Post-synaptic Changes

Alterations that occur in a neuron after neurotransmitter binding, leading to changes in excitability.

Synapse Structures

The complex formations at neuronal junctions through which signals are transmitted.

Motor Execution

The physical performance of a planned motor action.

Learning and Memory

Processes involving the acquisition, retention, and retrieval of information and skills.

Cognitive Flexibility

The mental ability to switch between thinking about two different concepts.

Acute vs Chronic Changes

Distinctions in brain adaptations that occur in short versus long durations.

Motor Sequence Learning

The process of learning and refining motor sequences through practice.

Frontal Eye Fields

Regions in the frontal lobe that are involved in the control of eye movements.

Acquisition of Skills

The process by which individuals develop capabilities to perform specific tasks proficiently.

Q: What is the main neurotransmitter decreased in Parkinson's disease within the basal ganglia?

A: Dopamine (produced by neurons in the substantia nigra pars compacta).

Q: What is the effect of dopamine loss in Parkinson’s on the basal ganglia pathways?

A: Decreased activation of the direct pathway and increased activation of the indirect pathway → overall reduction in movement (hypokinesia).

Q: Which basal ganglia structure shows degeneration in Huntington’s disease?

A: The caudate nucleus and putamen (collectively called the striatum).

Q: How does Huntington’s disease affect the basal ganglia motor pathways?

A: Degeneration of striatal neurons inhibits the indirect pathway → leading to excessive movement (hyperkinesia, chorea).

Q: In Parkinson’s disease, what happens to motor neuron activity in the cortex?

A: Motor cortex activity decreases, resulting in difficulty initiating voluntary movement.

Q: In Huntington’s disease, what happens to motor neuron activity in the cortex?

A: Motor cortex activity increases abnormally, causing uncontrolled movements.

Q: What neurotransmitter besides dopamine is involved in Huntington’s pathology?

A: GABA (γ-aminobutyric acid) — striatal neurons that normally release GABA degenerate.

Q: What role does the substantia nigra pars compacta play in Parkinson’s disease?

A: It supplies dopamine to the striatum, crucial for modulating motor pathways.

Q: Which basal ganglia pathway becomes overactive in Parkinson's disease?

A: The indirect pathway, leading to inhibition of movement.

Q: Which basal ganglia pathway becomes underactive in Huntington’s disease?

A: The indirect pathway, leading to excessive movement.yes

🧠 Normal Basal Ganglia Pathways

• Direct Pathway: Stimulates movement

• Indirect Pathway: Inhibits movement

• Balance between direct and indirect = smooth, controlled motion

🧠 Parkinson’s Disease

• Substantia nigra pars compacta degenerates → ↓ dopamine

• Direct pathway: Weakened (less stimulation of movement)

• Indirect pathway: Strengthened (more inhibition of movement)

• Result: Hypokinesia (slow, rigid movements, trouble starting movements)

🧠 Huntington’s Disease

• Striatum degenerates → ↓ GABAergic neurons

• Indirect pathway: Weakened (less inhibition of movement)

• Direct pathway: Relatively stronger (more stimulation of movement)

• Result: Hyperkinesia (involuntary movements like chorea)