The lizard cerebral cortex as a model to study neuronal regeneration

López‐García, Carlos; Molowny, A.; Nácher, Juan; Ponsoda, Xavier; Sancho-Bielsa, Francisco J.; Alonso-Llosa, Gregori

doi:10.1590/s0001-37652002000100006

Cited by 32 publications

(35 citation statements)

References 74 publications

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“…In this study, we report and characterize distributions of NADPHd+ and DCX+ neurons in the adult T. hispidus hippocampal formation, which is a structure with notably high neurogenic activity that is putatively homologous to the mammalian hippocampus [Font et al, 2002;López-García et al, 2002;Marchioro et al, 2005]. We found that the DMC (also called large-celled MC), especially the IPL, has a high density of NADPHd+ neurons, while the MC (also called small-celled MC) has a considerably lower density and a complete absence of NADPHd+ neurons in the CL.…”

Section: Discussionmentioning

confidence: 99%

Characterization of NADPH Diaphorase- and Doublecortin-Positive Neurons in the Lizard Hippocampal Formation

Macedo-Lima

Freire²,

Pimentel³

et al. 2016

Brain Behav Evol

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The lizard cortex has remarkable similarities with the mammalian hippocampus. Both regions process memories, have similar cytoarchitectural properties, and are important neurogenic foci in adults. Lizards show striking levels of widespread neurogenesis in adulthood and can regenerate entire cortical areas after injury. Nitric oxide (NO) is an important regulatory factor of mammalian neurogenesis and hippocampal function. However, little is known about its role in nonmammalian neurogenesis. Here, we analyzed the distribution, morphology, and dendritic complexity (Neurolucida reconstructions) of NO-producing neurons through NADPH diaphorase (NADPHd) activity, and how they compare with the distribution of doublecortin-positive (DCX+) neurons in the hippocampal formation of the neotropical lizard Tropidurus hispidus. NADPHd-positive (NADPHd+) neurons in the dorsomedial cortex (DMC; putatively homologous to mammalian CA3) were more numerous and complex than the ones in the medial cortex (MC; putatively homologous to the dentate gyrus). We found that NADPHd+ DMC neurons send long projections into the MC. Interestingly, in the MC, NADPHd+ neurons existed in 2 patterns: small somata with low intensity of staining in the outer layer and large somata with high intensity of staining in the deep layer, a pattern similar to the mammalian cortex. Additionally, NADPHd+ neurons were absent in the granular cell layer of the MC. In contrast, DCX+ neurons were scarce in the DMC but highly numerous in the MC, particularly in the granular cell layer. We hypothesize that NO-producing neurons in the DMC provide important input to proliferating/migrating neurons in the highly neurogenic MC.

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Section: Discussionmentioning

confidence: 99%

Characterization of NADPH Diaphorase- and Doublecortin-Positive Neurons in the Lizard Hippocampal Formation

Macedo-Lima

Freire²,

Pimentel³

et al. 2016

Brain Behav Evol

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“…A number of classical papers have described the structure and connections of the telencephalon of lizards from various squamate families, including actively foraging species, such as Tupinambis nigropunctatus (Lohman and Van WoerdenVerkley 1978) and T. teguxin (Teiidae; Lohman and Mentink 1972) and Podarcis hispanica (Lacertidae; Olucha et al 1988;Lopez-Garcia et al 2002), or sedentary species, such as Iguana iguana (Iguanidae ;Northcutt 1967;Bruce and Butler 1984) and Gekko gecko (Gekkonidae; Bruce and Butler 1984;Hoogland and Vermeulen-Vanderzee 1989). Anatomic forebrain atlases have been published for Anolis carolinensis (Greenberg 1982) and G. gecko (Smeets et al 1986).…”

Section: Introductionmentioning

confidence: 99%

Structural organization of the cerebral cortex of the neotropical lizard Tropidurus hispidus

et al. 2010

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Lizards belonging to the Tropiduridae family are "sit-and-wait" foragers, relying mainly on visual identification to catch prey that cross their visual fields. Little is known about the neurobiology of Tropiduridae lizards. We have used neurohistological techniques to study the structural organization of the telencephalon of the neotropical lizard Tropidurus hispidus, paying special attention to the cerebral cortex. As revealed by the Nissl technique and Golgi staining, the telencephalon of T. hispidus follows the squamate pattern, with some differences: the lateral cortex appears relatively atrophic, and most of the neuronal somata of the dorsal cortex are dispersed without forming a conspicuous cell layer. Golgi staining has revealed ten different neuronal types in the three cortical layers, based on somata shape and dendritic morphology: the granular (unipolar, bipolar, and multipolar), pyramidal (normal, inverted, open, bipyramidal, and horizontal), spherical horizontal, and fusiform neuronal types. The axon direction could be traced in five of the subtypes. We have also studied the distribution of zinc-enriched terminals in the telencephalon of T. hispidus by the Neo-Timm method. Some portions of the cortex, septum, striatum, and amygdaloid complex stain heavily, with patterns resembling those described for other lizard families. Thus, T. hispidus appears to be an interesting representative of the Tropiduridae family for further neurobiological comparative studies.

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“…Lesioning of the MC and DC of turtles produces deficits in spatial memory and the ability to navigate a maze [Rodriguez et al, 2002;López et al, 2003]. In squamate reptiles, lesioning of the MC causes similar disruption of the ability to navigate [Lopez-Garcia et al, 2002;Day et al, 2001]. Day et al [1999a, b; suggested that relative size differences in both the MC and DC of two lizards of the genus Acanthodactylus with contrasting spatial demands may not be related to differences in the lizards' ability to carry out bird-or mammallike spatial navigation, because no such differences were detected in laboratory tests aimed at quantifying such abilities.…”

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confidence: 99%

Experimentally Altered Navigational Demands Induce Changes in the Cortical Forebrain of Free-Ranging Northern Pacific Rattlesnakes <i>(Crotalus o. oreganus)</i>

et al. 2012

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The hippocampus of birds and mammals plays a crucial role in spatial memory and navigation. The hippocampus exhibits plasticity in adulthood in response to diverse environmental factors associated with spatial demands placed on an animal. The medial and dorsal cortices of the telencephalon of squamate reptiles have been implicated as functional homologues to the hippocampus. This study sought to experimentally manipulate the navigational demands placed on free-ranging northern Pacific rattlesnakes (Crotalus o. oreganus) to provide direct evidence of the relationship between spatial demands and neuroplasticity in the cortical telencephalon of the squamate brain. Adult male rattlesnakes were radio-tracked for 2 months, during which time 1 of 3 treatments was imposed weekly, namely 225-meter translocation in a random direction, 225-meter walk and release at that day’s capture site (handling control) or undisturbed (control). Snakes were then sacrificed and the brains were removed and processed for histological analysis of cortical features. The activity range was larger in the translocated (Tr) group compared to the handled (Hd) and undisturbed control (Cn) groups when measured via 95% minimum convex polygon (MCP). At the 100% MCP level, Tr snakes had larger activity ranges than the Cn snakes only. The volume of the medial cortex (MC) was larger in the Tr group compared to the Cn group. The MC of Hd snakes was not significantly different from that of either of the other groups. No differences in dorsal cortex (DC) or lateral cortex volumes were detected among the groups. Numbers of 5-bromo-2′-deoxyuridine (BrdU)-labeled cells in the MC and DC 3 weeks after BrdU injection were not affected by treatment. This study establishes a causal relationship between navigational demands and greater MC volume in a free-ranging reptile.

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The lizard cerebral cortex as a model to study neuronal regeneration

Cited by 32 publications

References 74 publications

Characterization of NADPH Diaphorase- and Doublecortin-Positive Neurons in the Lizard Hippocampal Formation

Characterization of NADPH Diaphorase- and Doublecortin-Positive Neurons in the Lizard Hippocampal Formation

Structural organization of the cerebral cortex of the neotropical lizard Tropidurus hispidus

Experimentally Altered Navigational Demands Induce Changes in the Cortical Forebrain of Free-Ranging Northern Pacific Rattlesnakes <i>(Crotalus o. oreganus)</i>

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