Multiple-unit responses to pitch changes in rabbits

Abstract

Yhteenveto: Aivovasteet kuuloarsykemuutoksiin kissoilla ja kaneilla. Diss.Brain responses to pitch changes were measured in cats and rabbits. Event related potentials (ERPs) were recorded from the hippocampus (cats and rabbits), cerebellar cortex, and visual cortex (rabbits). Additionally, multiple unit activity (MUA) was measured in rabbits from the same trials and through the same electrodes as the ERPs. Pitch changes were introduced by presenting pitch deviant tones (deviants) in a sequence of homogenous repeated tones (standards). Differences in ERPs to the deviants and those to the standards (MMN-like ERPs) were found in recordings from the hippocampus and cerebellar cortex but not from the visual cortex. They did not occur before 75 ms from tone onset. MMN-like MUA was, in tum, present within the 20 ms latency in the hippocampus. The MMN-like responses reflected the different presentation rates of the deviants and standards only. Therefore, the responses did not resemble the mismatch negativity (MMN) observed in the cerebral cortex in humans and thought to represent a comparison process detecting a mismatch between a sensory input by the deviant and a short-term memory trace of the preceding standards. The hippocampal MUA recordings revealed a fast (latency less than 20 ms) increase in spike activity, particularly to the standards, suggesting that the higher stimulus presentation rate did not result in refractoriness on the part of those neural ensembles that were activated by the stimulation, as has been proposed in the case of the reduced amplitude of the Nl deflection of ERPs in humans. Three main conclusions can be drawn. First, instead of a separate comparison process, the different presentation rate of each type of stimulus per se is sufficient to explain the observed differences between responses to the deviants and those to the standards. Second, rather than neural refractoriness, this effect may represent an active process related to the formation of the short-term memory trace of repeated stimuli. Thirdly, since the effect of the stimulus repetition rate can be related to the memory trace, the trace seems to be widely distributed in the brain.

Mismatch Responses in the Awake Rat: Evidence from Epidural Recordings of Auditory Cortical Fields

“…MMN-like responses have been successfully obtained in recordings from non-human primates (macaques, [18], [19]), rabbits [20], cats [21], mice [22] and guinea pigs [23]. In contrast, MMN studies in rats provide somewhat inconsistent results.…”

Change detection and difference detection of tone duration discrimination

“…To investigate this type of perception, a sequence of repetitive frequent (standard) stimuli and infrequent (deviant) stimuli (the oddball paradigm) was employed and elicits an eventrelated potential (ERP) that is called mismatch negativity (MMN) [1]. MMN is observed not only in humans [2][3][4][5], but also in many awake and anesthetized mammals, for example, monkey [6], cat [7,8], rabbit [9], mouse [10], and guinea pig [11,12]. To clarify the neuronal mechanisms of MMN, it is important to establish animal models of the brain response involved in MMN.…”

Automatic Sensory Predictions: A Review of Predictive Mechanisms in the Brain and Their Link to Conscious Processing

“…Interestingly, the MMN is described as a pre-attentive, automatic response, which can be elicited despite variations in states of wakefulness ( Sculthorpe et al, 2009 ), such as during sleep or anesthesia, coma, or states of altered awareness, including hypnosis and meditation ( Cahn and Polich, 2009 ; Chennu and Bekinschtein, 2012 ; Morlet and Fischer, 2014 ; Jamieson, 2016 ). In addition to extensive research in humans, MMN responses have also been recorded in cats ( Csépe et al, 1987 ; Pincze et al, 2001 ), monkeys ( Javitt et al, 1992 , 1994 ), rabbits ( Ruusuvirta et al, 1995 , 1996a , b ), guinea pigs ( Kraus et al, 1994 ), and rats ( Shiramatsu et al, 2013 ; Harms et al, 2014 ), via epidural EEG electrodes or cortical surface microelectrode arrays. Results are comparable, but not completely identical.…”