Table 3

Stimulation of the pre-commissural fornix in rodents, along with main findings

ProjectionsStudyModelStimulation patternMain findings
AllMamad 2015RatsTheta burstResets the spiking of hippocampal theta cells, increases theta synchronisation, entrains the spiking of hippocampal place cells
Cholinergic neurons and/or projections
Optogenetic excitation
Van der Casteele et al 2014Mice, with or without urethane anaesthesiaSine wave,
1–12 Hz
Enhance theta rythm, suppress peri-theta frequency bands
Dannenberg et al 2015Mice, under urethane anaesthesiaSquare pulses,
5–40 Hz
Increase firing of hippocampal inhibitory interneurons and decrease firing of principal cells
Their activation is required for theta synchronisation
Mamad et al 2015Rats, awakeSquare pulses,
8–10 Hz vs 50 Hz
The most potent effect on hippocampal theta amplitude was observed after
8–10 Hz stimulation and in a non-active behavioural state
GABAergic neurons and/or projections
Optogenetic excitation
Gangadharan et al 2016Mice, freely movingSquare pulses,
10 or 20 Hz
Enhance type 2 theta rhythm, object exploration and not open-field exploration behaviour
Glutamatergic neurons and/or projections
Optogenetic excitation
Fuhrmann et al 2015Mice, freely moving3–12 HzEnable initiation of locomotion and theta oscillations as well as the active regulation of locomotion speed
Robinson et al 2016Mice, freely moving4–12 HzMS glutamatergic neurons synchronise hippocampal theta rhythms whereas activation of their projections to the hippocampus through fornix stimulations has no effect on theta rhythms
  • MS, medial septum.