Domina Petric, MD

Premotor cortex, brainstem and

emotional motor system

Premotor cortex includes anterior portion of precentral gyrus and posterior parts of superior, middle and inferior frontal gyri.

Premotor cortex gives rise to descending projections to lower motor neurons.

It is a mosaic of areas with modular organisation.

Premotor cortex

Medial division of the premotor cortex corresponds

as supplementary motor area (SMA).

There is a part of medial premotor cortex that is

involved in the expression of emotional behavior.

There is also a part of medial premotor cortex

concerned with organising bimanual activites.

There is a division concerned with governing

voluntary saccadic eye movements (frontal eye

field).

Premotor cortex, medial part

In the lateral premotor cortex are present areas that are concerned with organising movements guided by sensory information, including social interactions.

Inferior lateral part is concerned with social communication.

Broca´s area is located in the posterior inferior lateral part of the premotor cortex: this area organizes the vocal motor apparatus for production of speech.

Premotor cortex, lateral part

Near the Broca´s area are parts of premotor cortex concerned with production of speech in written form.

Premotor cortex, lateral part

There is activation of mirror motor neurons when we do some movement and when we observe

another person doing the same movement.

Mirror motor neurons are located in lateral premotor cortex.

These neurons are important in understanding the intention of some motor act.

Mirror motor neurons

II.

BRAINSTEM UPPER MOTOR NEURONS

Reticular formation extends throughout the entire brainstem.

Lateral and medial vestibulospinal tract: adjustment of posture.

Lateral vestibulospinal tract from lateral vestibular nuclei goes ipsilaterally and terminates in the spinal

cord cell group concerned with extensor muscles tone (primarily in the lower extremities).

Vestibulospinal tracts

Medial vestibulospinal tract is bilateral and terminates among medial lower motor neuronal columns, mainly found in the cervical region of the spinal cord: vestibulocervical reflexes.

Vestibulospinal tracts

Visceral and somatic motor control.

Mesencephalic and rostral pontine reticular formation modulates forebrain activity.

Caudal pontine and medullary reticular formation is concerned with premotor coordination of lower somatic and visceral motor neuronal pools.

Reticulospinal system is concerned primarily with making anticipatory adjustments of posture.

Reticulospinal tract

It is a motor structure that integrates sensory information from vision, audition, pain and temperature sensation.

Superior colliculus

III.

EMOTIONAL MOTOR SYSTEMS

Volitional movement: descending pyramidal and

extrapyramidal projections from motor cortex and

brainstem

Lateral: fine control of

distal muscles of

extremities

Medial: posture and

proximal muscles of

extremities

Brainstem reticular

formation

Motor neuron poolsMotor neurons of cranial nerve nuclei

and ventral horn of the spinal cord

Autonomic preganglionic

neurons

Muscle contraction and

movement

Activation of smooth

muscles and glands

Emotional expression: descending extrapyramidal

projections from limbic centers of ventro-medial

forebrain and hypothalamus

Medial: gain setting,

rhythmical reflexes

Lateral: specific

emotional

behaviors

Pyramidal

pathway

Corticobulbar pathway

https://www.coursera.org/learn/medical-neuroscience/lecture: Leonard E. White, PhD, Duke

University

Literature