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1.
Sci Rep ; 10(1): 15971, 2020 09 29.
Article in English | MEDLINE | ID: mdl-32994413

ABSTRACT

Pigeons can successfully discriminate between sets of Picasso and Monet paintings. We recorded from three pallial brain areas: the nidopallium caudolaterale (NCL), an analogue of mammalian prefrontal cortex; the entopallium (ENTO), an intermediary visual area similar to primate extrastriate cortex; and the mesopallium ventrolaterale (MVL), a higher-order visual area similar to primate higher-order extrastriate cortex, while pigeons performed an S+/S- Picasso versus Monet discrimination task. In NCL, we found that activity reflected reward-driven categorisation, with a strong left-hemisphere dominance. In ENTO, we found that activity reflected stimulus-driven categorisation, also with a strong left-hemisphere dominance. Finally, in MVL, we found that activity reflected stimulus-driven categorisation, but no hemispheric differences were apparent. We argue that while NCL and ENTO primarily use reward and stimulus information, respectively, to discriminate Picasso and Monet paintings, both areas are also capable of integrating the other type of information during categorisation. We also argue that MVL functions similarly to ENTO in that it uses stimulus information to discriminate paintings, although not in an identical way. The current study adds some preliminary evidence to previous literature which emphasises visual lateralisation during discrimination learning in pigeons.


Subject(s)
Columbidae/physiology , Paintings/classification , Prefrontal Cortex/physiology , Visual Cortex/physiology , Animals , Behavior, Animal , Brain Mapping , Functional Laterality , Photic Stimulation , Reward
2.
Neurobiol Learn Mem ; 171: 107214, 2020 05.
Article in English | MEDLINE | ID: mdl-32205205

ABSTRACT

The avian Wulst is the pallial (analogous to mammalian cortex) termination point of the thalamofugal pathway, one of two main visual pathways in birds, and is considered to be equivalent to primate striate cortex. We recorded neuronal activity from the Wulst in pigeons during two versions of a delayed matching-to-sample procedure. Two birds were trained on a common outcomes (CO) procedure, in which correct responses following both the skateboarder and the flower stimuli were associated with reward. Two other birds were trained on a differential outcomes (DO) procedure in which correct responses following only the skateboarder stimulus were associated with reward, while correct responses following the flower stimulus were not rewarded. In line with previous studies, under CO conditions, and for both excitatory and inhibitory neurons, delay activity in the Wulst was significantly different from baseline activity following both sample stimuli, which may indicate that Wulst delay activity is a neural correlate of working memory for the sample stimulus. On the other hand, under DO conditions, Wulst delay activity appeared to be a neural correlate of the upcoming reward. We argue that Wulst neurons display flexibility in their encoding in that they can encode both sample and reward information, but may default to one type of coding over the other based on the demands of the task. The current study provides the first evidence that delay activity in the Wulst represents both a neural correlate for sample information as well as reward information.


Subject(s)
Brain/physiology , Conditioning, Operant/physiology , Discrimination Learning/physiology , Visual Pathways/physiology , Animals , Behavior, Animal/physiology , Columbidae , Neurons/physiology , Photic Stimulation
3.
Laterality ; 24(2): 125-138, 2019 Mar.
Article in English | MEDLINE | ID: mdl-29931998

ABSTRACT

The ability to speak is a unique human capacity, but where is it located in our brains? This question is closely connected to the pioneering work of Pierre Paul Broca in the 1860s. Based on post-mortem observations of aphasic patients' brains, Broca located language production in the 3rd convolution of the left frontal lobe and thus reinitiated the localizationist view of brain functions. However, contemporary neuroscience has partially rejected this view in favor of a network-based perspective. This leads to the question, whether Broca's findings are still relevant today. In this mini-review, we discuss current and historical implications of Broca's work by focusing on his original contribution and contrasting it with contemporary knowledge. Borrowing from Broca's famous quote, our review shows that humans indeed "speak with the left hemisphere"- but Broca's area is not the sole "seat of articulatory language".


Subject(s)
Aphasia, Broca/history , Broca Area/physiology , Functional Laterality , Neurosciences/history , Speech/physiology , Aphasia, Broca/physiopathology , History, 19th Century , Humans , Neural Pathways/physiology
4.
Mol Neurobiol ; 56(6): 3999-4012, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30242727

ABSTRACT

Myelination of axons in the central nervous system is critical for human cognition and behavior. The predominant protein in myelin is proteolipid protein-making PLP1, the gene that encodes for proteolipid protein, one of the primary candidate genes for white matter structure in the human brain. Here, we investigated the relation of genetic variation within PLP1 and white matter microstructure as assessed with myelin water fraction imaging, a neuroimaging technique that has the advantage over conventional diffusion tensor imaging in that it allows for a more direct assessment of myelin content. We observed significant asymmetries in myelin water fraction that were strongest and rightward in the parietal lobe. Importantly, these parietal myelin water fraction asymmetries were associated with genetic variation in PLP1. These findings support the assumption that genetic variation in PLP1 affects white matter myelination in the healthy human brain.


Subject(s)
Genetic Variation , Magnetic Resonance Imaging , Myelin Proteolipid Protein/genetics , Myelin Sheath/metabolism , Water/metabolism , White Matter/pathology , Adolescent , Adult , Age Factors , Aged , Female , Genotype , Humans , Male , Middle Aged , Neuroimaging , Polymorphism, Single Nucleotide/genetics , Young Adult
5.
Brain Struct Funct ; 223(8): 3875-3887, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30094605

ABSTRACT

The corpus callosum is the brain's largest commissural fiber tract and is crucial for interhemispheric integration of neural information. Despite the high relevance of the corpus callosum for several cognitive systems, the molecular determinants of callosal microstructure are largely unknown. Recently, it was shown that genetic variations in the myelin-related proteolipid 1 gene PLP1 and the axon guidance related contactin 1 gene CNTN1 were associated with differences in interhemispheric integration at the behavioral level. Here, we used an innovative new diffusion neuroimaging technique called neurite orientation dispersion and density imaging (NODDI) to quantify axonal morphology in subsections of the corpus callosum and link them to genetic variation in PLP1 and CNTN1. In a cohort of 263 healthy human adults, we found that polymorphisms in both PLP1 and CNTN1 were significantly associated with callosal microstructure. Importantly, we found a double dissociation between gene function and neuroimaging variables. Our results suggest that genetic variation in the myelin-related gene PLP1 impacts white matter microstructure in the corpus callosum, possibly by affecting myelin structure. In contrast, genetic variation in the axon guidance related gene CNTN1 impacts axon density in the corpus callosum. These findings suggest that PLP1 and CNTN1 gene variations modulate specific aspects of callosal microstructure that are in line with their gene function.


Subject(s)
Contactin 1/physiology , Corpus Callosum/anatomy & histology , Myelin Proteolipid Protein/physiology , Neurites , White Matter/anatomy & histology , Adolescent , Adult , Aged , Contactin 1/genetics , Diffusion Magnetic Resonance Imaging/methods , Female , Genotype , Humans , Male , Middle Aged , Myelin Proteolipid Protein/genetics , Myelin Sheath/genetics , Polymorphism, Single Nucleotide , Young Adult
6.
Behav Neurosci ; 131(3): 213-219, 2017 06.
Article in English | MEDLINE | ID: mdl-28471222

ABSTRACT

Four birds were trained on a delayed matching-to-sample task with common outcomes where correct responses during both red and green trials yielded reward. We recorded neuronal activity from the avian nidopallium caudolaterale, the avian equivalent of the mammalian prefrontal cortex, and the avian nidopallium frontolaterale, a higher-order visual processing region. In both regions we found sustained activity during the delay period of both red and green trials. These findings provide the first evidence that delay activity in the pigeon's nidopallium caudolaterale and nidopallium frontolaterale represent a neural correlate for the to-be-remembered sample stimulus. (PsycINFO Database Record


Subject(s)
Action Potentials/physiology , Columbidae/physiology , Discrimination Learning/physiology , Neurons/physiology , Prefrontal Cortex/cytology , Visual Perception/physiology , Animals , Photic Stimulation , Reward
7.
Behav Brain Res ; 317: 382-392, 2017 01 15.
Article in English | MEDLINE | ID: mdl-27720742

ABSTRACT

We recorded neuronal activity from the nidopallium caudolaterale, the avian equivalent of mammalian prefrontal cortex, and the entopallium, the avian equivalent of the mammalian visual cortex, in four birds trained on a differential outcomes delayed matching-to-sample procedure in which one sample stimulus was followed by reward and the other was not. Despite similar incidence of reward-specific and reward-unspecific delay cell types across the two areas, overall entopallium delay activity occurred following both rewarded and non-rewarded stimuli, whereas nidopallium caudolaterale delay activity tended to occur following the rewarded stimulus but not the non-rewarded stimulus. These findings are consistent with the view that delay activity in entopallium represents a code of the sample stimulus whereas delay activity in nidopallium caudolaterale represents a code of the possibility of an upcoming reward. However, based on the types of delay cells encountered, cells in NCL also code the sample stimulus and cells in ENTO are influenced by reward. We conclude that both areas support the retention of information, but that the activity in each area is differentially modulated by factors such as reward and attentional mechanisms.


Subject(s)
Brain Mapping , Delay Discounting/physiology , Neurons/physiology , Prefrontal Cortex/cytology , Reward , Visual Cortex/cytology , Action Potentials/physiology , Animals , Columbidae/physiology , Conditioning, Operant , Photic Stimulation
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