Table 1. Anatomy along with possible associated neurotransmitters and functions, as well as associated references of brainstem circuits.

Brainstem tracts	Gray/white matter structures in the brainstem tractographic pathways	Possible Neuro-transmitter	Related Functions	Associated References
MLF	Begin: ICP and ML;	Serotonin, Noradrenaline	wakefulness, pain control, maintaining posture, cardiovascular control, eye movement	[31–33]
	Pass: lower raphe nuclei, ML;
	End: MidB and RN
DLF	Begin: PAG and Surrounding area;	Serotonin, Noradrenaline,	wakefulness, attention, consciousness, stress and reward, pain	[34–40]
	Pass: LC, PAG;
	End: hypothalamus; mamillary body
SCP	Begin: SCP and cerebellar dentate nuclei;	Acetylcholine, GABA	sleep, cognition, mood, attention, arousal, voluntary limb movements, locomotion	[41–44]
	Pass: PPN;
	End: RN and thalamus
NST	Begin: SN	Dopamine, Serotonin	motor function, mood, pleasure and reinforcement	[40,45–47]
	Pass: VTA, STN
	End: putamen and GP
MFT	Begin: MidB and VTA	Acetylcholine, Dopamine	mood, word, reward and pleasure	[48–51]
	Pass: NAc, ATR
	End: rectal, orbitofrontal, and prefrontal cortices
FPT	Begin: medial 1/3 of the CP	Non-reticular system	control of movement, facial movement	[52,53]
	Pass: ALIC, SCR, frontal cortices
	End: superior frontal, supplementary motor area, and the premotor areas
CST	Begin: middle 1/3 of the CP	Non-reticular system	movement of body muscles	[54]
	Pass: PLIC
	End: precentral (primary motor) cortex
STT	Begin: ML	Non-reticular system	sensory of temperature, pain	[55,56]
	Pass: dorsal spinal cord, ML, thalamus
	End: postcentral (sensory) cortex
POTPT	Begin: lateral 1/3 of the CP	Non-reticular system	variety of functions: working memory, learning, visual, auditory	[57,58]
	Pass: ventral medulla, RLIC, dorsal thalamus, amygdala and hippocampus
	End: parietal, occipital, and temporal cortex

Abbreviations: ICP = inferior cerebellar peduncle; ML = medial lemniscus; MidB = midbrain; RN = red nucleus; PAG = periaquaductal grey matter; LC = locus coeruleus; SCP = superior cerebellar peduncle; PPN = pedunculopontine nucleus; SN = substantia nigra; VTA = ventral tegmental area; STN = subthalamic nucleus; GP = Globus pallidus; NAc = Nucleus Accumbens; ATR = anterior thalamic radiation; CP = cerebral peduncle; ALIC = anterior limb and genu of the internal capsule; SCR = superior coronal radiata; PLIC = posterior limb of the internal capsule; RLIC = retrolenticular part of the internal capsule.