Psychopharmacology

, Volume 220, Issue 3, pp 465–479

Mutual independence of 5-HT2 and α1 noradrenergic receptors in mediating deficits in sensorimotor gating

  • Sarah K. Baisley
  • Katherine L. Fallace
  • Abha K. Rajbhandari
  • Vaishali P. Bakshi
Original Investigation

DOI: 10.1007/s00213-011-2490-2

Cite this article as:
Baisley, S.K., Fallace, K.L., Rajbhandari, A.K. et al. Psychopharmacology (2012) 220: 465. doi:10.1007/s00213-011-2490-2

Abstract

Rationale

Prepulse inhibition (PPI), a preattentional information-filtering mechanism, is disrupted by serotonin (5-HT) or norepinephrine (NE) agonists to model deficits seen in schizophrenia, but whether this effect occurs through interactions between these systems is not known.

Objectives

These studies investigated whether PPI/activity changes induced by agonists of one system were dependent on neurotransmission within the other.

Methods

Male Sprague–Dawley rats received the 5-HT2 receptor agonist DOI (1-[2,5-dimethoxy-4-iodophenyl]-2-aminopropane) (0, 0.3 mg/kg), with or without antagonists for α1 (prazosin:0, 0.3, or 1 mg/kg) or β (timolol:0, 3, or 10 mg/kg) receptors or their combination (0 or 0.3 mg/kg prazosin + 3 mg/kg timolol), or the 5-HT2 antagonist ritanserin (0, 2 mg/kg). Separately, the α1-adrenergic receptor agonist cirazoline (0, 0.68 mg/kg) was given with and without ritanserin (0, 0.5, or 2 mg/kg) or the NE antagonists (0 or 0.3 mg/kg prazosin + 3 mg/kg timolol). Finally, combinations of subthreshold doses of DOI (0, 0.01, 0.025 mg/kg) and cirazoline (0, 0.1, 0.25 mg/kg) were tested for their ability to disrupt PPI, and concomitant administration of all three antagonists (0 vs. 0.3 mg/kg prazosin + 3 mg/kg timolol + 2 mg/kg ritanserin) was assessed for its ability to modify PPI. Locomotion was assessed in an additional set of experiments.

Results

Doses/combinations of prazosin and timolol that reversed cirazoline-induced effects did not alter DOI-induced effects, and ritanserin did not affect cirazoline at doses that blocked DOI-mediated effects. Concomitant antagonism of α1 + β + 5-HT2 receptors did not modify PPI, nor did combinations of subthreshold doses of cirazoline and DOI.

Conclusions

5-HT2 receptors and α1 and β NE receptors may act through independent mechanisms to modulate sensorimotor gating and locomotor activity.

Keywords

StartleSchizophreniaNoradrenergicSerotonergicLocomotionStereotypy

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Sarah K. Baisley
    • 1
    • 2
  • Katherine L. Fallace
    • 1
  • Abha K. Rajbhandari
    • 1
    • 2
  • Vaishali P. Bakshi
    • 1
    • 2
    • 3
  1. 1.Department of PsychiatryUW-MadisonMadisonUSA
  2. 2.Neuroscience Training ProgramUW-MadisonMadisonUSA
  3. 3.Department of PsychiatryUniversity of Wisconsin School of Medicine and Public HealthMadisonUSA