10. Dementia

What happens at the presynaptic neuron when an AP reaches it?

1. Activation of voltage-gated Ca channels 

2. Ca influx

3. Ca mediated vesicle docking and NT release 

What is glutamate responsible for?

Learning, working memory, cognitive processing

What is GABA responsible for?

Learning, working memory, anxiety

What is Dopamine responsible for?

Motor control, cognition, judgement, impulsivity, attention/ Alertness: working mem, motivation, clarity

What is serotonin used for?

Moodiness, anxiety/ Satisfaction: learning memory, pleasure/pain, relaxation

What is Norepinephrine used for?

Moodiness, anxiety/ concentration: execution, perseverance, recall memory.

What is Acetylcholine used for?

Cognitive functions

What is glycine used for?

Cognition, mood

What NT are considered Monoamine NT?

• Serotonin 

• Dopamine

• Norepinephrine 

What can low dopamine levels result in?

Parkinson’s disease, decreased ability to move properly; resulting in stiffness, tremors or shaking 

How can low dopamine or problems using dopamine affect the thinking and feeling regions of the brain?

May contribute to schizophrenia or ADHD (attention deficit hyperactivity disorder)

What NT is released during stress?

Norepinephrine

What neurotransmitter is involved in emotional arousal, attention, stress, anxiety, and mood disorders?

Norepinephrine

What role does norepinephrine play in drug dependence?

It contributes to anxiety and stress responses associated with drug dependence.

Which disorders are associated with norepinephrine imbalance?

Depression and ADHD

What functions doe4s serotonin control?

Mood, appetite, and sleep

What levels of serotonin are correlated with depression?

Lower levels of serotonin is correlated with depression

How do most depression medications work?

They aim to block reuptake of serotonin. 

What type of neurotransmitter is glutamate?

Excitatory neurotransmitter

What does an excitatory neurotransmitter do?

Increases the chance that a neuron will fire

How abundant is glutamate in the brain?

It is among the most abundant neurotransmitters

What role does glutamate play in brain function?

Enhances electrical flow required for normal function. It is important for early brain development. Also involved in learning and memory.

What mental disorders are linked to low glutamate levels?

• Autism

• Obsessive Compulsive Disorder (OCD)

• Schizophrenia

• Alzheimer's disease

• Depression

What is the most significant inhibitory NT?

GABA

What does GABA do?

It opens Cl ion channels to hyperpolarize the synapse.

Why would drugs target GABA?

To treat epilepsy. 

What drugs affect GABA?

• Barbiturates

• Tranquilizers (Valium, Xanax)

• Alcohol

What is Glycine involved in?

• Immune response 

• Mood, cognition, and pain perception 

What does glycine do?

It activates Cl channesl and produces hyperpolarization.

What does ACh bind to?

Nicotinic and muscarinic receptors.

What is ACh used in?

Sensory processing, attention, and memory.

What is Low ACh associated with?

Dementia/Alzheimer’s

What is dementai?

An umbrella term that describes a set of symptoms causing a person to have changes in brain function that interfere with ability to function and do everyday activities. 

What are the symptoms of dementia?

• Cognition: memory, language, orientation, judgment, and planning

• Behavior: depression, anxiety, agitation, hallucinations, paranoia, and aggressiveness

• Other: Weight loss, incontinence, gait disturbances, sleep disturbances

What are the goals of treatment in dementia?

• Improve or preserve activities of daily living (ADL) function

• Reduce caregiver durgen

• Enhance quality of life

What are the treatment strategies of dementia?

• Increase ACh signaling via AChEsterase inhibitors 

• Decease glutamate signaling via inhibiting NMDA receptors 

How does glutamate contribute to dementia?

Excess glutamate causes overstimulation of NMDA receptors, reducing synaptic NMDA receptor activity and activating extrasynaptic NMDA receptors, which promotes neuronal apoptosis.

What is Donepezil (Aricept)?

A cholinesterase inhibitor used in dementia treatment.

What is Memantine (Namenda)?

A NMDA glutamate receptor agonist used in dementia treatment.

What other agents are used to treat associated symptoms of dementia?

• Depression via SSRIs

• Psychosis via anti-psychotics

• Sleep disturbances via benzodiazepines etc.