title: Developmental changes in GABAergic neurotransmission to presympathetic and cardiac parasympathetic neurons in the brainstem.
abstract: Cardiovascular function is regulated by a dynamic balance composed of sympathetic and parasympathetic activity. Sympathoexcitatory presympathetic neurons (PSNs) in the rostral ventrolateral medulla project directly to cardiac and vasomotor sympathetic preganglionic neurons in the spinal cord. In proximity to the PSNs in the medulla, there are preganglionic cardiac vagal neurons (CVNs) within the nucleus ambiguus, which are critical for parasympathetic control of heart rate. Both CVNs and PSNs receive GABAergic synaptic inputs that change with challenges such as hypoxia and hypercapnia (H/H). Autonomic control of cardiovascular function undergoes significant changes during early postnatal development; however, little is known regarding postnatal maturation of GABAergic neurotransmission to these neurons. In this study, we compared changes in GABAergic inhibitory postsynaptic currents (IPSCs) in CVNs and PSNs under control conditions and during H/H in postnatal day 2-5 (P5), 16-20 (P20), and 27-30 (P30) rats using an in vitro brainstem slice preparation. There was a significant enhancement in GABAergic neurotransmission to both CVNs and PSNs at age P20 compared with P5 and P30, with a more pronounced increase in PSNs. H/H did not significantly alter this enhanced GABAergic neurotransmission to PSNs in P20 animals. However, the frequency of GABAergic IPSCs in PSNs was reduced by H/H in P5 and P30 animals. In CVNs, H/H elicited an inhibition of GABAergic neurotransmission in all ages studied, with the most pronounced inhibition occurring at P20. In conclusion, there are critical development periods at which significant rearrangement occurs in the central regulation of cardiovascular function.
authors: Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037, USA. olgad@gwu.edu
authors: Olga
authors: O
authors: Dergacheva
authors: Carie R
authors: CR
authors: Boychuk
authors: David
authors: D
authors: Mendelowitz
mesh_terms: D000818:Animals; D001933:Brain Stem / Q000254:growth & development* / Q000503:physiopathology; D006321:Heart / Q000294:innervation*; D006935:Hypercapnia / Q000503:physiopathology; D000860:Hypoxia / Q000503:physiopathology; D066298:In Vitro Techniques; D009474:Neurons / Q000502:physiology*; D010275:Parasympathetic Nervous System / Q000254:growth & development* / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
chemical_list: D005680:gamma-Aminobutyric Acid
keywords: brainstem; development; neurons; parasympathetic; presympathetic
references: J Appl Physiol (1985). 2010 Dec;109(6):1686-96
references: 20930126
references: Arch Dis Child. 1998 May;78(5):481-3
references: 9659101
references: J Comp Neurol. 1984 Sep 10;228(2):168-85
references: 6480910
references: J Appl Physiol (1985). 2011 Sep;111(3):825-33
references: 21680874
references: Neurosci Lett. 2002 Nov 8;332(3):195-9
references: 12399013
references: Eur J Pediatr. 1988 Jan;147(1):74-8
references: 3338482
references: Semin Perinatol. 2006 Apr;30(2):73-6
references: 16731280
references: Hypertension. 2012 Dec;60(6):1491-7
references: 23108653
references: J Neurosci. 2004 Oct 20;24(42):9261-8
references: 15496661
references: Am J Physiol. 1994 Jan;266(1 Pt 2):R245-56
references: 8304547
references: J Am Soc Nephrol. 2002 Jan;13(1):35-41
references: 11752019
references: Am J Physiol. 1967 Mar;212(3):595-602
references: 6020532
references: J Neurophysiol. 2009 Mar;101(3):1141-50
references: 19091927
references: J Appl Physiol (1985). 1998 Dec;85(6):2066-74
references: 9843527
references: Pediatrics. 1994 Jan;93(1):44-9
references: 8265322
references: News Physiol Sci. 1999 Aug;14:155-161
references: 11390842
references: J Neurosci. 1984 Feb;4(2):474-94
references: 6699683
references: Biol Neonate. 1994;65(3-4):194-7
references: 8038282
references: Am J Physiol. 1998 Apr;274(4):R1099-110
references: 9575975
references: Clin Exp Pharmacol Physiol. 2002 May-Jun;29(5-6):514-21
references: 12010201
references: Ann N Y Acad Sci. 2001 Jun;940:237-46
references: 11458681
references: Nat Methods. 2011 Sep;8(9):745-52
references: 21985008
references: Brain Res. 2003 Nov 21;991(1-2):84-95
references: 14575880
references: Am J Physiol. 1995 Dec;269(6 Pt 2):R1356-69
references: 8594938
references: Brain Res. 2002 Mar 8;929(2):181-90
references: 11864623
references: J Appl Physiol (1985). 2004 Oct;97(4):1431-6
references: 15155710
references: Am J Physiol. 1996 Dec;271(6 Pt 2):H2609-14
references: 8997322
references: J Neurosci Methods. 2006 Dec 15;158(2):251-9
references: 16842860
references: Am J Physiol. 1982 Jul;243(1):R92-8
references: 6178303
references: Pediatr Res. 2000 Aug;48(2):140-2
references: 10926286
references: Pediatr Res. 1988 Dec;24(6):677-82
references: 3205622
references: Neuroscience. 1998 Jan;82(2):429-42
references: 9466452
references: J Pediatr. 1980 Jul;97(1):51-5
references: 7381648
references: Am J Physiol. 1984 Apr;246(4 Pt 2):R570-7
references: 6144273
references: Pflugers Arch. 1997 Aug;434(4):438-44
references: 9211810
references: Am J Physiol. 1996 Nov;271(5 Pt 2):R1304-10
references: 8945968
references: Sleep. 1988 Oct;11(5):413-24
references: 3227221
references: Natl Vital Stat Rep. 2008 Jul 30;57(2):1-32
references: 18972721
references: Pediatr Rev. 2002 Jan;23(1):3-9
references: 11773587
references: Brain Res. 2001 Jan 19;889(1-2):78-83
references: 11166689
references: Neuroscience. 2012 May 3;209:12-20
references: 22390944
references: Annu Rev Physiol. 1988;50:511-24
references: 3288103
references: Neuroscience. 1993 Jun;54(3):729-43
references: 8332259
references: Exp Neurol. 2011 Dec;232(2):212-21
references: 21945005
references: J Appl Physiol (1985). 1989 May;66(5):2384-90
references: 2745303
references: Pediatr Res. 1999 Mar;45(3):350-4
references: 10088653
references: J Auton Nerv Syst. 1982 Jan;5(1):9-22
references: 6173408
references: J Appl Physiol Respir Environ Exerc Physiol. 1982 Dec;53(6):1330-5
references: 7153133
references: Physiol Rev. 1994 Apr;74(2):323-64
references: 8171117
references: Am J Physiol Regul Integr Comp Physiol. 2000 Jul;279(1):R39-46
references: 10896862
references: J Pediatr. 1987 May;110(5):669-78
references: 3553512
references: Am J Physiol. 1999 Sep;277(3):H1069-80
references: 10484430
references: J Appl Physiol (1985). 1999 Jul;87(1):203-10
references: 10409576
references: Pediatr Pathol. 1991 Sep-Oct;11(5):677-84
references: 1745639
references: Circ Res. 1985 Mar;56(3):359-69
references: 3971510
references: Clin Exp Pharmacol Physiol. 2002 Apr;29(4):261-8
references: 11985533
references: Sleep. 2012 Feb 01;35(2):177-86
references: 22294807
references: J Physiol. 1994 Apr 1;476(1):101-16
references: 8046626
references: Neuroscience. 2009 Dec 15;164(3):1191-8
references: 19772899
references: Hypertension. 2009 Feb;53(2):370-4
references: 19029485