Nero Anatomy

quiz 3

Tectum

• Inferior Colliculus

• Superior Colliculus

• Cerebral Aqueduct

• Periaqueductal Gray

Tegmentum

• Red Nucleus

• Substantia Nigra

• Reticular Formation

• Medial Lemniscus

Basis Pedunculi

Cerebral Peduncles

Inferior Colliculus

Most dorsal part of the midbrain plays a role
in auditory system

Superior Colliculus

Most dorsal part of midbrain plays a role
in controlling eye movement

Cerebral Aqueduct

Supplies CSF, connects the third and
fourth ventricles

Periaqueductal Gray

Surrounds the cerebral aqueduct, pain
suppression

Red Nucleus

Plays role in motor control, (connections from cerebellum, spinal cord, and cortex) and goal directed behavior

Substantial Nigra

It contains dopaminergic nuclei and projects to
basal ganglia to control movement

Reticular Formation (Green)

Neurons that regulate arousal by influencing the excitability of neurons throughout the CNS

Medial Lemniscus (Purple)

Axonal projections of dorsal column nuclei transmitting touch and limb position

Cerebral Peduncles (Orange)

Axons of the Corticospinal Tract transmitting voluntary motor movement

Major Structures within the Pons

• Medial Lemniscus

• Reticular Formation

• Pontine Nuclei

• Fourth Ventricle

Medial Lemniscus (Purple)

Axonal projections of dorsal column nuclei transmitting touch and limb position

Reticular Formation (Green)

Neurons that regulate arousal by influencing the excitability of neurons throughout the CNS

Pontine Nuclei (Orange)

Neurons that transmit information for skilled motor control from the cerebral cortex to the cerebellum

Fourth Ventricle

Supplies CSF, dorsal to the medulla and ventral to the cerebellum

Major Structures within the Medulla

• Pyramids

• Dorsal Column Nuclei

• Medial Lemniscus

• Reticular Formation

• Inferior Olivary Nucleus

• Fourth Ventricle

Pyramids (Orange)

Axons of the Corticospinal Tract transmitting
voluntary motor movement

Dorsal Column Nuclei (Yellow)

First synapse of the dorsal column – medial lemniscus system transmitting touch and limb position

Medial Lemniscus (Purple)

Axonal projections of dorsal column nuclei transmitting touch and limb position

Reticular Formation (Green)

Neurons that regulate arousal by influencing the excitability of neurons throughout the CNS

Inferior Olivary Nucleus

Neurons that project to the cerebellum and integrate sensory and motor information

Fourth Ventricle

Supplies CSF, dorsal to the medulla and ventral
to the cerebellum

Acetylcholine: Originate

basal forebrain (basal nucleus within the hypothalamus),
reticular formation

Acetylcholine: Projections

cerebral cortex and hippocampal formation

Acetylcholine: Functions

Sympathetic and parasympathetic systems, neuromuscular junction for muscle contraction, learning and memory, brain rhythms during sleep and wake

Alzheimer’s Disease

loss/degeneration of cholinergic neurons result in memory and cognitive decline

Dopamine: Originate

Substantia Nigra (midbrain) and Ventral Tegmental Area

Dopamine: Projections

Basal Ganglia (Striatum) and portions of the frontal lobe

Dopamine: Functions

Reward and motivated behavior, cognitive control, and initiation of movement

Parkinson’s Disease

Loss of dopaminergic neurons in substantia nigra results in slowed movement and tremor

Schizophrenia

Changes in DA signals result in symptoms of schizophrenia-like hallucination, delusions, anhedonia, and lack of motivation

Norepinephrine/Noradrenaline: Originate

Locus Ceruleus

Norepinephrine/Noradrenaline: Projections

Throughout the cerebral cortex, thalamus, amygdala, hippocampal formation

Norepinephrine/Noradrenaline: Functions

Arousal and transition to wake, attention, response to stress (fight or flight response)

Depression

Reduced Norepinephrine to the limbic the system can result in feelings of depression

Attention Deficit Hyperactivity Disorder

Reduced norepinephrine in the prefrontal cortex can result in decreased attention and impulse control

Serotonin: Originate

Raphe Nuclei throughout the brainstem

Serotonin: Projections

Throughout the cerebral cortex and thalamus

Serotonin: Functions

Regulation of mood, learning and memory, and pain

Depression and anxiety

Decreased levels of serotonin throughout the brain results in changes in mood, feelings of depression and anxiety, and difficulty with sleep and memory

Modulatory Systems

• Alter firing activity, increase/decrease voltage-dependent currents, alter synaptic efficacy, increase burst activity, reconfigure synaptic connectivity (modulate the actions of other neural systems)
• Acetylcholine, Dopamine, Noradrenaline, Serotonin

Diffuse Projecting system

unlike motor and sensory systems which tend to project to a specific target, these modulatory systems project throughout the entire brain