Control of ICP by The Medullary Reticular Formation

Spontaneous episodic elevation of intracranial pressure (ICP), named “plateau wave” by Lundberg [4], often occurs in patients with increased ICP caused by brain tumor, hydrocephalus and other conditions. There are two possible causes for the development of plateau waves: persistent intracranial hypertension and cerebral vasomotor reaction [2]. Plateau waves are associated with increased cerebral blood volume (CBV) [9] due to dilatation of the cerebral blood vessels, and apparently result from intact autoregulation responding to changes in cerebral perfusion pressure (CPP) [7, 10]. Previously, we investigated the function of noradrenergic cell groups, especially the dorsal noradrenergic system (locus coeruleus complex, LC), and the cholinoceptive pontine area (CPA) [3] in the generation of plateau waves in ICP-VI [5] and VII [6]. This study investigated the function of the ventral noradrenergic system [1] (medullary reticular formation, MRF) in the control of ICP and neuronal organizations between the CPA and MRF.