Underweight rats have enhanced dopamine release and blunted acetylcholine response in the nucleus accumbens while bingeing on sucrose.
The present study tested whether rats release more accumbens dopamine (DA) during a sugar binge when they are underweight vs. normal weight. Since acetylcholine (ACh) in the nucleus accumbens (NAc) normally increases as a meal progresses and satiety ensues, we also tested whether ACh release is altered when an animal has lost weight. Rats were maintained on daily 8-h access to chow, with 10% sucrose solution available for the first 2 h. Microdialysis performed on day 21, at normal body weight, revealed an increase in extracellular DA to 122% of baseline in response to drinking sucrose. Extracellular ACh peaked at the end of the meal. Next, the rats were food and sucrose restricted so that by day 28 they were at 85% body weight. When retested, these animals released significantly more DA when drinking sucrose (179%), but ACh release failed to rise. A control group was tested in the same manner but given sugar only on days 1, 21 and 28. At normal body weight, control animals showed a non-significant rise in DA when drinking sucrose on day 21. On day 28, at 85% body weight, the controls showed a small increase (124%) in DA release; however, this was significantly lower than the 179% observed in the underweight rats with daily sugar access. These findings suggest that when an animal binges on sugar and then loses weight, the binge releases significantly more DA and less ACh than when animals are at a normal body weight.
Avena
N M
NM
Department of Psychology, Princeton University, Princeton, NJ 08540, USA.
Rada
P
P
Hoebel
B G
BG
D000109:Acetylcholine / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D001835:Body Weight / Q000502:physiology*; D002032:Bulimia; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004298:Dopamine / Q000378:metabolism*; D005508:Food Deprivation / Q000502:physiology; D008297:Male; D017551:Microdialysis; D009714:Nucleus Accumbens / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013395:Sucrose / Q000008:administration & dosage*; D013549:Sweetening Agents / Q000008:administration & dosage*; D013997:Time Factors
D013549:Sweetening Agents; D013395:Sucrose; D000109:Acetylcholine; D004298:Dopamine
Curr Opin Pharmacol. 2007 Dec;7(6):617-27
18023617
Neuroscience. 2001;104(3):791-8
11440810
J Neurosci Methods. 1980 Dec;3(2):129-49
6110810
Drug Alcohol Depend. 1985 Nov;16(2):95-109
4075974
J Neurosci. 1995 Nov;15(11):7189-95
7472473
Obes Res. 1995 Nov;3 Suppl 4:525S-529S
8697053
Psychopharmacology (Berl). 1985;85(4):419-25
3927337
J Neurosci. 1995 Nov;15(11):7181-8
7472472
Alcohol Drug Res. 1985-1986;6(1):37-48
3878146
Physiol Behav. 2004 Aug;82(1):123-30
15234600
Neuroscience. 2005;134(3):737-44
15987666
J Neurochem. 1992 Jun;58(6):2269-74
1573406
Obesity (Silver Spring). 2008 Sep;16(9):1998-2002
19186326
Exp Clin Psychopharmacol. 2007 Oct;15(5):481-91
17924782
J Neurosci. 1998 Sep 15;18(18):7502-10
9736668
Neuroscience. 2006;139(3):813-20
16460879
Am J Physiol Regul Integr Comp Physiol. 2006 Nov;291(5):R1236-9
16763080
Physiol Behav. 1998 Dec 1;65(3):545-53
9877422
Psychopharmacology (Berl). 2000 Oct;152(2):200-7
11057524
Physiol Behav. 2002 Jul;76(3):353-64
12117572
Proc Natl Acad Sci U S A. 1988 Jul;85(14):5274-8
2899326
Prog Neuropsychopharmacol Biol Psychiatry. 2008 Apr 1;32(3):620-8
18262320
J Neurosci. 1995 Jul;15(7 Pt 2):5169-78
7623143
Pharmacol Biochem Behav. 1983 Sep;19(3):453-5
6685315
Psychopharmacology (Berl). 1997 May;131(1):1-8
9181629
Eur J Neurosci. 1999 Dec;11(12):4389-97
10594666
Pharmacol Biochem Behav. 1979 Jan;10(1):155-9
35792
J Neurosci. 2002 May 1;22(9):3306-11
11978804
Pharmacol Biochem Behav. 1986 Sep;25(3):623-7
3774828
Behav Neurosci. 2005 Oct;119(5):1207-14
16300427
Neurosci Biobehav Rev. 2008;32(1):20-39
17617461
Life Sci. 1986 Dec 29;39(26):2629-37
2432375
J Pharmacol Exp Ther. 1983 Oct;227(1):28-34
6684685
J Psychiatry Neurosci. 2004 Mar;29(2):134-7
15069467
Curr Opin Pharmacol. 2007 Feb;7(1):69-76
17174602
Eur J Neurosci. 2005 Dec;22(12):3229-40
16367789
Philos Trans R Soc Lond B Biol Sci. 2006 Jul 29;361(1471):1149-58
16874930
J Neurosci. 1995 Oct;15(10):6640-50
7472425
Int J Eat Disord. 1997 Dec;22(4):411-20
9356889
Int J Eat Disord. 2006 Jan;39(1):76-9
16254868
Eur J Neurosci. 2003 Oct;18(8):2326-34
14622194
Am J Clin Nutr. 1985 Nov;42(5 Suppl):1133-50
2865893