My research focuses on how the brain encodes, integrates and retains information, specifically in the domains of perception and memory formation. To study the underpinnings of these cognitive operations I record the electrical activity of ensembles of neurons simultaneously in different parts of the brain while rats perform on learning and sensory discrimination tasks.
A new line of research focusses on multi-modal sensory integration, the process by which information from different sensory modalities can be bound together into one object of segregated into multiple objects. Our subjective experience of an object or scene is generally a unified percept composed of pieces of information from different sensory modalities. For example, when we see a teacup falling on the floor and simultaneously hear the sound of breaking glass, our perceptual systems seem to effortlessly integrate the sensory inputs from different modalities and attribute them to the same event. The binding of sensory features is thought to occur across an extensive network of sensory and associational cortices and connected thalamic nuclei, but the neural mechanisms for linking and integrating perceptual representations are largely unknown. We investigate how stimuli are integrated in early sensory brain areas as well as higher integrative-multimodal centers and how these areas interact to collectively code multimodal percepts. This research is supported by a NWO Veni grant.
Another research interest is how associations are formed between spatial locations and rewards. Two brain areas that are involved in the learning of such associations are the hippocampus, which processes spatial or contextual information and the ventral striatum, that focuses on the emotional or motivational value of environmental cues. The ventral striatum receives a strong hippocampal input of spatial-contextual information, and we are interested to find out how its neural ensembles integrate this information to invigorate reward-directed behaviors.
In previous work we demonstrated that the combination of spatial and emotional aspects of a learning experience is replayed by hippocampus and ventral striatum during sleep, a phenomenon believed to critically contribute to the consolidation and strengthening of memory traces. This “offline” reactivation is coordinated such that the spatial information in the hippocampus is reactivated shortly before the emotional information in the ventral striatum. The information is replayed about ten times faster in sleep than during the actual experience, at a time scale that is optimal for the cellular strengthening of synaptic connections in the brain. These results contribute to our understanding of the distributed way the brain processes, links and retrieves different aspects of memories.
Lansink CS, Jackson JC, Lankelma JV, Ito R, Everitt BJ, Robbins TW, Pennartz CMA (2012) Reward cues in space: commonalities and differences in neural coding by hippocampal and ventral striatal ensembles. J. Neurosci. 32: 12444-12459.
Oleson EB, Beckert MV, Morra JT, Lansink CS, Cachope R, Abdullah RA, Loriaux AL, Schetters D, Pattij T, Roitman MF, Lichtman AH, Cheer JF (2012). Endocannabinoids shape accumbal encoding of cue-motivated behavior via CB1 receptor activation in the ventral tegmentum. Neuron 73(2):360-73.
Lansink CS, Goltstein PM, Lankelma JV, Pennartz CM (2010). Fast-spiking interneurons of the rat ventral striatum: temporal coordination of activity with principal cells and responsiveness to reward. Eur J Neurosci. 32(3):494-508.
Kalenscher T, Lansink CS, Lankelma JV, Pennartz CM. (2010). Reward-associated gamma oscillations in ventral striatum are regionally differentiated and modulate local firing activity. J Neurophysiol. 103(3):1658-72.
Lansink CS, Goltstein PM, Lankelma JV, McNaughton BL, Pennartz CM. (2009) Hippocampus leads ventral striatum in replay of place-reward information. PLoS Biol. 7(8):e1000173.
Lansink CS, Goltstein PM, Lankelma JV, Joosten RN, McNaughton BL, Pennartz CM. (2008) Preferential reactivation of motivationally relevant information in the ventral striatum. J Neurosci. 28(25):6372-82.
Lansink CS, Bakker M, Buster W, Lankelma J, van der Blom R, Westdorp R, Joosten RN, McNaughton BL, Pennartz CM (2009). A split microdrive for simultaneous multi-electrode recordings from two brain areas in awake small animals. J Neurosci Methods. 162:129-38.