thalamus hypothalamus gaj.ppt

Diencephalon:Thalamus and Hypothalamus

January 13, 2009

Diencephalon

• Relay between the brainstem & cerebral cortex• Dorsal-posterior structures

– Epithalamus• Habenular nuclei – integrate smell & emotions• Pineal gland – monitors diurnal / nocturnal rhythm

– Thalamus– Metathalamus

• Medial geniculate body – auditory relay• Lateral geniculate body – visual relay

• Ventral-anterior structure– Hypothalamus

Function of the Thalamus• Sensory relay

– ALL sensory information (except smell)

• Motor integration– Input from cortex, cerebellum

and basal ganglia• Arousal

– Part of reticular activating system

• Pain modulation– All nociceptive information

• Memory & behavior– Lesions are disruptive

Input to the Thalamus

Input to the Thalamus

Metathalamus Vision and Hearing

Input to the Thalamus

Sensory relay - Ventral posterior group all sensation from body and head, including pain

Input to the Thalamus

Motor control and integration

Input to the Thalamus

Behavior and emotion connection with hypothalamus

Projections from the Thalamus

Metathalamus Vision and Hearing

Proyecciones desde el Tálamo

Sensory relay Ventral posterior group

all sensation from body and head, including pain.

Projections from the Thalamus

Motor control and integration

Projections from the Thalamus

Behavior and emotion connection with hypothalamus

Thalamus: axial view

Descending upper motor neurons

Cerebral peduncles Internal capsule

Thalamus: axial view

Thalamus: sagittal view

Pons

Thalamus: sagittal view

Thalamus: coronal view

Thalamus: coronal view

3rd ventricle

Thalamus: coronal view

Internal capsule

Thalamus: coronal view

Internal capsule

Cerebral peduncles

Thalamus: coronal view

Mediodorsal nucleus Internal capsule

Dorsomedial nucleus has reciprocal connections to prefrontal cortex.

Concerned with judgment, decision making, memory and behavior.

Thalamus

Mediodorsal nucleus Internal capsule

Ventral lateral nucleus

VL nucleus has reciprocal connections with primary motor cortex. It receives input from cerebellar nuclei.

With VA nucleus (which receives input from basal ganglia) contributes to planning and control of movement.

Thalamus: blood supply

Hypothalamus

Located ventral-anterior to thalamus.

(Subthalamus, located ventral to thalamus, will be discussed with basal ganglia.)

Hypothalamus

Coronal view

Hypothalamus

Sagittal view

Hypothalamus

Hypothalamus

Thalamus

Hypothalamus

Optic chiasm

Hypothalamus

Pituitary Gland

Hypothalamus

Mammillary body: termination of fornix

Hypothalamus

Fornix: part of the limbic system

Hypothalamus

Fornix to mammillary bodies

Coronal view

Lateral view

Hypothalamus: sagittal view

Hypothalamus: sagittal view

Hypothalamus: sagittal view

Hypothalamus: sagittal view

Connects temporal lobes, sharing olfactory and audiovisual information

Hypothalamus: coronal view(rostral to caudal)

PRE-OPTIC

SUPRACHIASMATIC

TUBERAL

MAMMILLARY

Hypothalamus: coronal view

Gonadotropic releasing hormone

Sexual arousal, appetite, reproduction

Pre-Optic Region

Hypothalamus: coronal view

Hypothalamus: coronal view

Hypothalamus: coronal view

Secrete ADH, oxytocin

Transported via axons to posterior pituitary (hypophysis)

Suprachiasmic Region

Hypothalamus: coronal view

Regulates thirst

Hypothalamus: coronal view

Body temperature

Circadian rhythms

Hypothalamus: coronal view

Hypothalamus: coronal view

Satiety

Tuberal Region

Hypothalamus: coronal view

Regulates prolactin and growth hormone

β endorphin for pain

Hypothalamus: coronal view

Hypothalamus: coronal view

Limbic system

Mammillary region

Hypothalamus: coronal view

Hypocretin (orexin)

Narcolepsy, reward

Hypothalamus

Relationship to Pituitary Gland

Hypothalamic Connections

Anterior pituitary

From Pre-optic nucleus

Tubero-infundibular tract to Median eminence, then via Portal veins

Gonadotropic releasing hormone

Hypothalamic Connections

Posterior pituitary

Supraoptic-hypophyseal tract

ADH / Vasopressin (supraoptic nuclei)

Oxytocin (paraventricular nuclei)

Function of the Pituitary

Weds

Basal ganglia