Psychopharmacology

, Volume 202, Issue 1–3, pp 207–223

RO4938581, a novel cognitive enhancer acting at GABAA α5 subunit-containing receptors

  • Theresa M. Ballard
  • Frédéric Knoflach
  • Eric Prinssen
  • Edilio Borroni
  • Jeffrey A. Vivian
  • Jennifer Basile
  • Rodolfo Gasser
  • Jean-Luc Moreau
  • Joseph G. Wettstein
  • Bernd Buettelmann
  • Henner Knust
  • Andrew W. Thomas
  • Gerhard Trube
  • Maria-Clemencia Hernandez
Original Investigation

Abstract

Rationale

GABAA α5 subunit-containing receptors are primarily expressed in the hippocampus and their role in learning and memory has been demonstrated recently by both genetic and pharmacological approaches.

Objectives

The objective of the study is to evaluate the cognitive effects of a novel GABAA α5 receptor inverse agonist, RO4938581 in rats and monkeys.

Materials and methods

The in vitro profile was determined using radioligand binding and electrophysiological assays for the GABAA α1, α2, α3, and α5 receptors. Long-term potentiation (LTP) was performed in mouse hippocampal slices. Cognitive effects were assessed in rats in the delayed match to position (DMTP) task and the Morris water maze. In monkeys, the object retrieval task was used. Pro-convulsant and anxiogenic potentials were evaluated in mice and rats. In vivo receptor occupancy was determined using [3H]-RO0154513.

Results

RO4938581 is a potent inverse agonist at the GABAA α5 receptor, with both binding and functional selectivity, enhancing hippocampal LTP. RO4938581 reversed scopolamine-induced working memory impairment in the DMTP task (0.3–1 mg/kg p.o.) and diazepam-induced spatial learning impairment (1–10 mg/kg p.o.). RO4938581 improved executive function in monkeys (3-10 mg/kg p.o.). Importantly, RO4938581 showed no anxiogenic and pro-convulsive potential. RO4938581 dose-dependently bound to GABAA α5 receptors and approximately 30% receptor occupancy was sufficient to produce enhanced cognition in the rat.

Conclusions

The data further support the potential of GABAA α5 receptors as a target for cognition-enhancing drugs. The dual binding and functional selectivity offers an ideal profile for cognition-enhancing effects without the unwanted side effects associated with activity at other GABAA receptor subtypes.

Keywords

GABAA receptors Benzodiazepine Inverse agonist Long-term potentiation Cognition Delayed match to position Morris water maze Object retrieval Monkey Rat 

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Theresa M. Ballard
    • 1
  • Frédéric Knoflach
    • 1
  • Eric Prinssen
    • 1
  • Edilio Borroni
    • 1
  • Jeffrey A. Vivian
    • 1
    • 2
    • 3
  • Jennifer Basile
    • 1
    • 2
  • Rodolfo Gasser
    • 1
  • Jean-Luc Moreau
    • 1
  • Joseph G. Wettstein
    • 1
  • Bernd Buettelmann
    • 1
  • Henner Knust
    • 1
  • Andrew W. Thomas
    • 1
  • Gerhard Trube
    • 1
  • Maria-Clemencia Hernandez
    • 1
  1. 1.CNS Research, F. Hoffmann-La Roche Ltd.BaselSwitzerland
  2. 2.CNS Research, Roche BiosciencePalo AltoUSA
  3. 3.Department of Integrative Systems NeuroscienceMerck Research LaboratoriesWest PointUSA

Personalised recommendations