The thalamus is the large mass of gray matter in the dorsal part of the diencephalon of the brain with several functions such as relaying of sensory signals, including motor signals, to the cerebral cortex and the regulation of consciousness, sleep, and alertness.

2. The thalamus (from Greek = inner chamber)
is a midline symmetrical structure within
the brains of vertebrates including humans,
situated between the cerebral
cortex and midbrain. Its function includes
relaying sensory and motor signals to the
cerebral cortex, along with the regulation of
consciousness, sleep, and alertness.

3.  The thalamus comprises
right and left halves, each
egg-shaped which form
the walls of the third
ventricle.
 The two halves are joined
in the midline by an
intrathalamic adhesion or
massa intermedia.
 Each hemi thalamus is
divided into 3 main groups
of nuclei (medial, anterior,
and ventral-posterior).

5.  From a functional viewpoint, there are 2 major
classes of thalamic nuclei:
1.Specific
2.Nonspecific.
 “Specific” Nuclei are so called because they are
interconnected with localized regions of the
cerebral cortex.
 “Non-specific” Nuclei are interconnected in a
diffuse manner to many cortical regions.

8. 1. Somatosensory relay nuclei: The ventroposterior
nuclear complex receives somatosensory information
about the contralateral half of the body and face, and
that it projects to the ipsilateral somatosensory cortex.
2. Visual relay nucleus: The lateral geniculate nucleus
receives input from the retina via the optic tract and
projects to primary visual cortex (area 17).
3. Auditory relay nucleus: The medial geniculate
nucleus receives auditory input from inferior colliculus
and projects to primary auditory cortex (superior
temporal gyrus).

9. The ventral lateral and ventral anterior nuclei
provide information which influence posture and
movement.
The anterior and dorsomedial nuclei provide
input to the cerebral cortex from areas of the
brain involved in learning, memory, and the
control of emotions.

10. The pulvinar, lateral dorsal, and lateral
posterior nuclei are particularly developed to
carry out higher order functions such as speech.

12.  The midline, intralaminar and centromedian
nuclei are non-specific nuclei. The are
thought of as an extension of the brainstem
reticular formation and thus regulate
alertness and deep sleep.

14. 1. It acts as a relay between a variety of subcortical areas
and the cerebral cortex.
2. Role in regulating states of sleep and wakefulness. Thus
damage to the thalamus can lead to permanent coma.
3. Thalamus is functionally connected to the hippocampus. So,
it is crucial for human episodic memory. The thalamic
regions also provide differentiation of the functioning of
recollective and familiarity memory.
4. The thalamus provides the specific channels from the
basal ganglia and cerebellum to the cortical motor areas.

16.  It is a condition developed after a stroke
causing damage to the thalamus.
 Ischemic strokes and Hemorrhagic
strokes can cause lesions in the thalamus.
 8% of all stroke patients experience thalamic
pain syndrome.
 Symptoms are preceded by numbness in the
affected side leading to burning, tingling
sensations and hypersensitivity (allodynia).

17.  Medical
1. Opiod Analgesics (Codeine & Morphine)
2. Anti-depressents (Amitriptyline)
3. Anti-convulsants (Pregabalin)
 Electical stimulation
1. Brain stimulation
2. Spinal cord stimulation (cheap & less
invasive)
 Radiation therapy (Long term treatment)

18.  Wikipedia, the free encyclopedia.
 Guyton’s text book of Physiology
 Lecture 33. The Thalamus by C.Chalk