Brain Stimulation as a Cue for Event-Related Potentials in Rat Cortex: Amphetamine Effects

Abstract

Slow potential (SP) responses were recorded bilaterally from the frontal cortex of rats with permanently implanted silver-silver chloride electrodes. Trials were presented at variable intervals from 15 to 50 sec and the interval between the pulse cue and onset of the rewarding train was 2 sec. The cue stimulus was a single 0.5 msec monophasic square wave pulse of the same current intensity as rewarding stimulation (100 Hz, 500 msec train). Appropriate current strength was determined by prior testing for self-stimulation. The single pulse by itself failed to evoke an SP response but after repeated pairings, large negative SP responses developed which were bilaterally equal. These responses extinguished rapidly when rewarding stimulation was discontinued. d-Amphetamine (0.125, 0.25 and 0.5 mg/kg, SC) produced a dose-related depression of the SP response to the pulse cue, an effect comparable to that observed using an auditory cue with either food or MFB stimulation reinforcement. The results indicate that frontal cortex SP responses which develop in anticipation of a meaningful event do not require a peripheral sensory cue. Furthermore, amphetamine suppression of these SP responses is not produced via a disruption of the auditory system.

The ventral pallidum: Subregion-specific functional anatomy and roles in motivated behaviors

“…Similar to the human CNV, shifts in rat SP reflects learning of the association between the CS+ and a reward, and the SP also shows extinction upon removal of the reward. These SP characteristics are independent of the CS modality (tone, light or subthreshold brain stimulation) and type of reinforcer (food, rewarding brain stimulations, footshock) (Rucker et al, 1986; Pirch, 1993), and clearly involve dopaminergic transmission (Pirch et al, 1981; Pirch, Napier and Corbus, 1981; Pirch and Corbus, 1983). The SPs correlate with event-related changes in single neuron firing in both the frontal cortex (Pirch and Peterson, 1981; Pirch et al, 1985) as well as in the VP (Rigdon and Pirch, 1986; note: only a caudal portion of VP was tested, which was termed the substantia innominata in this report).…”

A new approach to assess gambling-like behavior in laboratory rats: using intracranial self-stimulation as a positive reinforcer

“…They allowed rats to work for this electrical brain stimulation (EBS) by responding on an operant manipulandum (e.g., pressing a lever, spinning a wheel) (Olds and Milner, 1954). The discovery of this technique has been instrumental in mapping reward pathways throughout the brain, and while there are many regions of the brain that can be used to support ICSS (Olds and Milner, 1954; Wise and Bozarth, 1981; Wise, 1996), it is well-documented that stimulation of the medial forebrain bundle (MFB) promotes profound and reliable behavioral outputs (Corbett and Wise, 1980; Pirch et al, 1981; McCown et al, 1986; Tehovnik and Sommer, 1997). Stimulation current parameters can be manipulated to affect the reinforcing value of the EBS and therefore alter ICSS behavior.…”

Novel physiological paradigm for assessing reward anticipation and extinction using cortical direct current potential responses in rats

“…In a groundbreaking study, Pirch et al investigated slow potentials following warning stimuli using a feeding reward task involving lever pressing and an ICSS task with MFB stimulation under anesthesia [18][19][20] . Their research illustrated a negative slow potential response in the cortex prior to reward presentation, along with differences in DC potential responses between reinforced and non-reinforced stimuli that align with our ndings [18][19][20] .…”

“…Therefore, identifying brain activity related to anticipation necessitates the use of physiological measures with high temporal resolution, such as electroencephalogram (EEG), in addition to frequently used brain imaging techniques such as fMRI [17] . Event-related slow potential (ERP) is an EEG component that arises during movement preparation or predictive anticipation of upcoming rewarding events while awaiting reward completion [18][19][20] . Although this slow potential component can be extracted during alternating current (AC) EEG recording, accurate capture of the phenomenon becomes challenging owing to the decrease in slow potential amplitude with short time constants [21] .…”