Midbrain or Mesencephalon Ventral surface Posterior surface.

Midbrain or MesencephalonMidbrain or Mesencephalon

Ventral surface

Posterior surface

Lateral surface

Tectum

Cerebral peduncle

Section paralell to the inferior colliculus

1- inf colliculus nuclei 2- parabigeminal area 3- periaqueductal gray mater 4- mesencephalic nucleus of v nerve 5- trochlear nucleus 6-substantia nigra 7- ventral tegmental area of Tsai 8- interpeduncular nucleus

1- inf. colliculus nuclei

External nucleus

1- Inferior colliculus

2- Parabigeminal Area

3- Periaqueductal gray mater

4- Mesencephalic nucleus of trigeminal nerve

Pesudounipolar neuron

4- Mesencephalic nucleus of trigeminal nerve

5- Trochlear nucleus(IV)

5- Trochlear nucleus

5- Trochlear nucleus

6- substantia nigra

dopam

inGABA Pars com

pact

Pars re

ticular

6- substantia nigra

6- substantia nigra

6- substantia nigra

(resting tremor)

Experimental parkinsonExperimental parkinson

MonkeyMonkey

Meperidine analogeMeperidine analoge

Like MPTP(1methyl 4phenyl 1,2,3,6 Like MPTP(1methyl 4phenyl 1,2,3,6 tetrahydropyridine)tetrahydropyridine)

7- Ventral tegmental area of Tsai

pleasure

8- Interpeduncular nucleus

Important pathways

1-Curs cerebri 2-medial lemniscus 3- lateral lemniscus 4- spinal and trigeminal lemniscus 5- Decussation of the sup. Cerebellar

peduncle 6- Medial longituidinal fasiculus

Crus cerebri

Section paralell to the superior colliculus

1- sup. colliculus nuclei 2- periaqueductal gray mater 3- mesencephalic nucleus of v nerve 4- occulomotor nuclear complex 5- red nucleus 6-substantia nigra 7- ventral tegmental area of Tsai 8- interpeduncular nucleus

sup. colliculus nuclei

1

2

3

4

5

sup. colliculus nuclei

sup. colliculus nuclei

3- occulomotor nuclear complex

Edinger westphal

Edinger westphal

Edinger westphal

red nucleus

Caudal magnocellular

Rostral parvicellularred nucleus

kennedy (1990)kennedy (1990)

Rubrospinal pathwayRubrospinal pathway

Corticospinal pathwayCorticospinal pathway