The long-range goal of this research is to characterize the CNS pathways that control basal sympathetic nerve discharge (SND) and cardiovascular function. Since 1990, the PI has studied the control of the 10-Hz rhythm that is the predominant feature of SND in decerebrate or urethane- anesthetized cats. This rhythm is highly coherent in nerves controlling a variety of cardiovascular target organs and may be a prerequisite for inducing the complex patterns of spinal sympathetic outflow that accompany some behavioral states. Studies during the current funding period are the first to identify specific CNS sites that regulate this activity. Data from antidromic activation experiments have indicated reciprocal connections between some of these areas and pharmacologic studies have suggested neurotransmitter systems that are important in the control of the 10 hz rhythm in SND. In the proposed 5-yr research plan, state-of-the-art electrophysiologic and analytic techniques will be combined with microiontophoresis and microinjection of drugs to address 4 Specific aims: (1) To test the hypothesis that pontine neurons in the A5, A6 and parabrachial/Kolliker- Fuse complex are involved in the control of the 10 Hz rhythm, (2) To identify the interconnections and signs (excitation or inhibition) of synaptic connections among brainstem neurons with activity correlated to the 10 Hz rhythm in SND, (3) To test the hypothesis that the 10 Hz rhythm is generated by a distributed network of brainstem neurons, and (4) to identify the central sites where serotonergic and catecholaminergic neurons act to affect the balance between the 10 Hz rhythm and the irregular 2-6 Hz oscillations in SND. These studies will enhance our understanding of the central circuitry responsible for generating and controlling the 10 Hz rhythm in resting SND.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37HL033266-14
Application #
2519279
Study Section
Experimental Cardiovascular Sciences Study Section (ECS)
Project Start
1987-09-30
Project End
2000-08-31
Budget Start
1997-09-01
Budget End
1998-08-31
Support Year
14
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Michigan State University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
193247145
City
East Lansing
State
MI
Country
United States
Zip Code
48824
Barman, Susan M (2016) What can we learn about neural control of the cardiovascular system by studying rhythms in sympathetic nerve activity? Int J Psychophysiol 103:69-78
Barman, Susan M; Orer, Hakan S (2010) Rostral ventrolateral medullary but not medullary lateral tegmental field neurons mediate sympatho-sympathetic reflexes in cats. Am J Physiol Regul Integr Comp Physiol 299:R1269-78
Barman, Susan M; Gebber, Gerard L (2009) The posterior vermis of the cerebellum selectively inhibits 10-Hz sympathetic nerve discharge in anesthetized cats. Am J Physiol Regul Integr Comp Physiol 297:R210-7
Orer, Hakan S; Gebber, Gerard L; Barman, Susan M (2008) Role of serotonergic input to the ventrolateral medulla in expression of the 10-Hz sympathetic nerve rhythm. Am J Physiol Regul Integr Comp Physiol 294:R1435-44
Barman, Susan M; Kenney, Michael J (2007) Methods of analysis and physiological relevance of rhythms in sympathetic nerve discharge. Clin Exp Pharmacol Physiol 34:350-5
Barman, Susan M; Gebber, Gerard L (2007) Role of ventrolateral medulla in generating the 10-Hz rhythm in sympathetic nerve discharge. Am J Physiol Regul Integr Comp Physiol 293:R223-33
Gebber, Gerard L; Orer, Hakan S; Barman, Susan M (2006) Fractal noises and motions in time series of presympathetic and sympathetic neural activities. J Neurophysiol 95:1176-84
Gebber, Gerard L; Barman, Susan M; Fadel, Paul J (2006) Fractal fluctuations in breath number, period, and amplitude are independently controlled in awake, healthy humans. Conf Proc IEEE Eng Med Biol Soc 1:4615-8
Orer, Hakan S; Gebber, Gerard L; Barman, Susan M (2006) Medullary lateral tegmental field neurons influence the timing and pattern of phrenic nerve activity in cats. J Appl Physiol 101:521-30
Phillips, Shaun W; Gebber, Gerard L; Barman, Susan M (2005) Medullary lateral tegmental field: control of respiratory rate and vagal lung inflation afferent influences on sympathetic nerve discharge. Am J Physiol Regul Integr Comp Physiol 288:R1396-410

Showing the most recent 10 out of 64 publications