Final Neuro Study Guide 3

Class 6:
- Understand terminology associated with CNS anatomy including planes of
dissection, directionality, and white vs. grey matter.

- Lobes of the cerebrum
- Cerebrum (telencephalon) vs. diencephalon vs. brainstem
- Primary vs. unimodal vs. multimodal association cortices (sensory)
- Pre-frontal association cortices vs. pre-motor vs. primary motor areas
Class 7:
- What happens to neurotransmitters once they are released from the presynaptic
terminal (i.e. receptor binding and neurotransmitter clearance from the synapse)
- A neuron on produces one neurotransmitter but can have receptors for many
neurotransmitters. Know where the neurotransmitters are released vs. detected
in a neuron.
- Where does glutamate reuptake occur?
- Voltage gated vs. ligand gated ion channels
- Effect of neurotransmitter on the post synaptic voltage is dependent on the ions
the receptor is permeable to
- What glutamate receptors did we discuss in class? What ions are they
permeable to?
- What is a reversal potential? What is the reversal potential for glutamate
receptors?
- What are some behavioral effects of not being able to clear glutamate from
synapses (ie too much glutamate transmission in the brain)?—seizures
Class 8:
- Why was ketamine developed and what were its uses prior to 2006 (when
approved for depression treatment)?
- Therapeutic range for ketamine compared to other anesthetics
- Why is ketamine considered a “dirty” drug?
- What is one of the major receptor targets of ketamine? Define ketamine as a use
dependent blocker at this target.
- Full agonist vs. partial agonist vs. antagonist vs. reverse agonist
- Disinhibition as an explanation for why ketamine has different effects on behavior
at different doses.
Class 9:
- What neurotransmitter is GABA derived from?

- Where does GABA reuptake occur?
- What types of GABA receptors did we discuss in class? What ions are GABAA
receptors permeable to?
- What is the reversal potential for GABA receptors?
- What is the difference in how benzodiazepines and barbiturates interact with the
GABAA receptor? Why do physicians prefer prescribing benzos over barbs?
- Be able to define allosteric modulator vs. direct agonist.
- What is one mechanism for the withdrawal effects from benzodia

• Terminology associated with CNS anatomy: Understand basic terminology used in studying the central nervous system (CNS), including:

  • Planes of dissection: Reference points used to divide the body or brain into sections for study, including sagittal, coronal, and transverse planes.

  • Directionality: Terms describing the position of structures relative to each other (e.g., anterior, posterior, medial, lateral, superior, inferior).

  • White vs. grey matter: White matter consists of myelinated axons, allowing for communication between different brain regions, while grey matter consists of neuronal cell bodies, where processing occurs.

• Lobes of the cerebrum: The brain's cerebral cortex is divided into lobes: frontal, parietal, temporal, and occipital, each associated with different functions such as reasoning, sensory perception, language, and vision.

• Cerebrum (telencephalon) vs. diencephalon vs. brainstem: The cerebrum (telencephalon) is involved in higher cognitive functions; the diencephalon includes structures like the thalamus and hypothalamus, critical for sensory processing and endocrine functions; the brainstem controls basic life functions like heartbeat and breathing.

• Primary vs. unimodal vs. multimodal association cortices:

  • Primary cortices: Regions responsible for initial processing of sensory or motor information.

  • Unimodal association cortices: Areas for higher-level processing of a single type of sensory information.

  • Multimodal association cortices: Integrate information from multiple sensory modalities to contribute to complex behaviors and decision making.

• Pre-frontal association cortices vs. pre-motor vs. primary motor areas:

  • Pre-frontal association cortices: Involved in executive functions, decision making, and social behavior.

  • Pre-motor areas: Responsible for planning and coordinating movements; they prepare motor cortex for executing movements.

  • Primary motor areas: Directly involved in controlling voluntary motor movements.

Class 7:

• Neurotransmitter release and clearance: After neurotransmitters are released from presynaptic terminals, they bind to receptors on the postsynaptic neuron. They then need to be cleared from the synapse, either through reuptake by transporters or degradation by enzymes to terminate the signal.

• Neurotransmitter specificity: Each neuron typically produces one neurotransmitter but can express various receptors for different neurotransmitters, allowing for multifunctional signaling.

• Glutamate reuptake location: Glutamate reuptake occurs primarily in astrocytes surrounding the synaptic cleft.

• Ion channels:

  • Voltage gated ion channels: Open or close in response to changes in membrane potential.

  • Ligand gated ion channels: Open in response to the binding of neurotransmitters, allowing ions to flow across the membrane depending on the receptor type.

• Postsynaptic response: The change in voltage of the postsynaptic neuron depends on the types of ions the receptor allows to enter or leave the cell (e.g., Na+, K+, Ca2+, or Cl-).

• Glutamate receptors discussed in class: Key glutamate receptors include NMDA (N-Methyl-D-Aspartate) and AMPA receptors, which are permeable to Na+ and Ca2+ ions.

• Reversal potential: The reversal potential is the membrane potential at which there is no net flow of ions through the channel. For glutamate receptors, it is generally positive due to the ions they are permeable to (typically around +40 mV).

• Effects of glutamate clearance failure: An inability to clear glutamate can lead to excessive excitation in the brain, potentially causing seizures.

Class 8:

• Ketamine's development and uses: Ketamine was initially developed as an anesthetic for surgical procedures before its off-label use in treating chronic pain and depression after 2006.

• Ketamine's therapeutic range: Compared to traditional anesthetics, ketamine has a wider therapeutic range, making it effective at lower doses without typically causing respiratory depression.

• Dirty drug concept: Ketamine is termed a "dirty drug" because it affects multiple receptor systems and pathways, leading to various physiological and psychological effects, complicating its classification and effects.

• Major receptor target: One major target of ketamine is the NMDA receptor, where it acts as a use-dependent blocker, inhibiting its activity mainly when the receptor is activated.

• Types of agonists:

  • Full agonist: Activates the receptor fully to produce a maximal response.

  • Partial agonist: Activates the receptor but produces a less than maximal response compared to a full agonist.

  • Antagonist: Blocks the receptor and prevents activation.

  • Reverse agonist: Binds to the receptor and produces the opposite effect of an agonist.

• Disinhibition: Ketamine may cause different behavioral effects depending on the dose due to disinhibition mechanisms, impacting neurotransmitter function and brain circuits.

Class 9:

• GABA synthesis: GABA is derived from the neurotransmitter glutamate through the action of the enzyme glutamic acid decarboxylase (GAD).

• GABA reuptake: GABA reuptake occurs primarily in the presynaptic neuron and surrounding glial cells, ensuring signal termination.

• Types of GABA receptors discussed: GABA has two main receptor types: GABAA (ionotropic) and GABAB (metabotropic). GABAA receptors are primarily permeable to Cl- ions.

• Reversal potential for GABA: The reversal potential for GABAA receptors is typically negative, around -70 to -90 mV, leading to hyperpolarization of the postsynaptic neuron upon activation.

• Benzodiazepines vs. barbiturates: Benzodiazepines enhance the effect of GABA at the GABAA receptor with a safer profile and less risk of lethal overdose compared to barbiturates, which also depress the central nervous system. This makes physicians prefer prescribing benzodiazepines over barbiturates.

• Modulators: An allosteric modulator binds to a receptor and alters its response to an agonist, whereas a direct agonist binds to the active site and activates the receptor directly.

• Withdrawal effects from benzodiazepines: Withdrawal from benzodiazepines can be caused by the body’s adaptation to the presence of the drug, leading to increased receptor sensitivity and dependence on the drug for normal function.zepines ### Class 6: - Terminology associated with CNS anatomy: Undersd basic terminology used in studying the central nervous system (CNS), including: - Planes of dissection: Reference points used to divide the body or brain into sections for study, including sagittal, coronal, and transverse planes. - Directionality: Terms describing the position of structures relative to each other (e.g., anterior, posterior, medial, lateral, superior, inferior). - White vs. grey matter: White matter consists of myelinated axons, allowing for communication between different brain regions, while grey matter consists of neuronal cell bodies, where processing occurs. - Lobes of the cerebrum: The brain's cerebral cortex is divided into lobes: frontal, parietal, temporal, and occipital, each associated with different functions such as reasoning, sensory perception, language, and vision. - Cerebrum (telencephalon) vs. diencephalon vs. brainstem: The cerebrum (telencephalon) is involved in higher cognitive functions; the diencephalon includes structures like the thalamus and hypothalamus, critical for sensory processing and endocrine functions; the brainstem controls basic life functions like heartbeat and breathing. - Primary vs. unimodal vs. multimodal association cortices: - Primary cortices: Regions responsible for initial processing of sensory or motor information. - Unimodal association cortices: Areas for higher-level processing of a single type of sensory information. - Multimodal association cortices: Integrate information from multiple sensory modalities to contribute to complex behaviors and decision making. - Pre-frontal association cortices vs. pre-motor vs. primary motor areas: - Pre-frontal association cortices: Involved in executive functions, decision making, and social behavior. - Pre-motor areas: Responsible for planning and coordinating movements; they prepare motor cortex for executing movements. - Primary motor areas: Directly involved in controlling voluntary motor movements. ### Class 7: - Neurotransmitter release and clearance: After neurotransmitters are released from presynaptic terminals, they bind to receptors on the postsynaptic neuron. They then need to be cleared from the synapse, either through reuptake by transporters or degradation by enzymes to terminate the signal. - Neurotransmitter specificity: Each neuron typically produces one neurotransmitter but can express various receptors for different neurotransmitters, allowing for multifunctional signaling. - Glutamate reuptake location: Glutamate reuptake occurs primarily in astrocytes surrounding the synaptic cleft. - Ion channels: - Voltage gated ion channels: Open or close in response to changes in membrane potential. - Ligand gated ion channels: Open in response to the binding of neurotransmitters, allowing ions to flow across the membrane depending on the receptor type. - Postsynaptic response: The change in voltage of the postsynaptic neuron depends on the types of ions the receptor allows to enter or leave the cell (e.g., Na+, K+, Ca2+, or Cl-). - Glutamate receptors discussed in class: Key glutamate receptors include NMDA (N-Methyl-D-Aspartate) and AMPA receptors, which are permeable to Na+ and Ca2+ ions. - Reversal potential: The reversal potential is the membrane potential at which there is no net flow of ions through the channel. For glutamate receptors, it is generally positive due to the ions they are permeable to (typically around +40 mV). - Effects of glutamate clearance failure: An inability to clear glutamate can lead to excessive excitation in the brain, potentially causing seizures. ### Class 8: - Ketamine's development and uses: Ketamine was initially developed as an anesthetic for surgical procedures before its off-label use in treating chronic pain and depression after 2006. - Ketamine's therapeutic range: Compared to traditional anesthetics, ketamine has a wider therapeutic range, making it effective at lower doses without typically causing respiratory depression. - Dirty drug concept: Ketamine is termed a "dirty drug" because it affects multiple receptor systems and pathways, leading to various physiological and psychological effects, complicating its classification and effects. - Major receptor target: One major target of ketamine is the NMDA receptor, where it acts as a use-dependent blocker, inhibiting its activity mainly when the receptor is activated. - Types of agonists: - Full agonist: Activates the receptor fully to produce a maximal response. - Partial agonist: Activates the receptor but produces a less than maximal response compared to a full agonist. - Antagonist: Blocks the receptor and prevents activation. - Reverse agonist: Binds to the receptor and produces the opposite effect of an agonist. - Disinhibition: Ketamine may cause different behavioral effects depending on the dose due to disinhibition mechanisms, impacting neurotransmitter function and brain circuits. ### Class 9: - GABA synthesis: GABA is derived from the neurotransmitter glutamate through the action of the enzyme glutamic acid decarboxylase (GAD). - GABA reuptake: GABA reuptake occurs primarily in the presynaptic neuron and surrounding glial cells, ensuring signal termination. - Types of GABA receptors discussed: GABA has two main receptor types: GABAA (ionotropic) and GABAB (metabotropic). GABAA receptors are primarily permeable to Cl- ions. - Reversal potential for GABA: The reversal potential for GABAA receptors is typically negative, around -70 to -90 mV, leading to hyperpolarization of the postsynaptic neuron upon activation. - Benzodiazepines vs. barbiturates: Benzodiazepines enhance the effect of GABA at the GABAA receptor with a safer profile and less risk of lethal overdose compared to barbiturates, which also depress the central nervous system. This makes physicians prefer prescribing benzodiazepines over barbiturates. - Modulators: An allosteric modulator binds to a receptor and alters its response to an agonist, whereas a direct agonist binds to the active site and activates the receptor directly. - Withdrawal effects from benzodiazepines: Withdrawal from benzodiazepines can be caused by the body’s adaptation to the presence of the drug, leading to increased receptor sensitivity and dependence on the drug for normal function.