Journal of Comparative Neurology最新文献

{"title":"Dopaminergic Innervation of the Nidopallium Caudolaterale in the Japanese Quail","authors":"Defne Albayrak,&nbsp;Sinem Gencturk,&nbsp;Kevin B. Haselhuhn,&nbsp;Cem Sevinc,&nbsp;Onur Güntürkün,&nbsp;Mehdi Behroozi,&nbsp;Noemi Rook,&nbsp;Gunes Unal","doi":"10.1002/cne.70154","DOIUrl":"10.1002/cne.70154","url":null,"abstract":"<p>Convergent evolution illustrates how distantly related lineages develop comparable traits and abilities in response to similar ecological pressures. In birds, the nidopallium caudolaterale (NCL) is an executive function hub analogous to the mammalian prefrontal cortex, despite their distant roots and major differences in gross structure. While the NCL has been studied in pigeons, songbirds, and chickens, its organization in other Galliformes remains unclear. Here, we investigated the NCL in the Japanese quail (<i>Coturnix japonica</i>), a Galliform species commonly used in studies of reproductive behavior and appetitive conditioning. Using immunohistochemistry for tyrosine hydroxylase, we mapped dopaminergic projections from the ventral tegmental area and substantia nigra, quantified fiber density relative to surrounding pallial regions, and characterized axonal arborizations. We identified postsynaptic targets of tyrosine hydroxylase-positive fibers and examined their neurochemical profiles, including putative glutamatergic neurons expressing CaMKIIa and interneuron subpopulations expressing parvalbumin, calbindin, calretinin, or secretagogin. The NCL of the Japanese quail exhibited dense dopaminergic innervation primarily targeting principal neurons, with only sparse <i>en passant</i> contacts on interneuron populations, following the pattern observed in other Galliformes. These findings indicate that dopaminergic modulation of the NCL is conserved across Galliformes and support the use of the Japanese quail as a model for studying executive circuits and cognitive neurobiology in birds.</p>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 4","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13033471/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147574218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brain Morphology and Quantitative Assessment of Sensory Brain Areas in Southern Bluefin Tuna, Thunnus maccoyii (Scombridae, Teleostei)","authors":"Myoung Hoon Ha,&nbsp;Lucille Chapuis,&nbsp;Rebecca Glarin,&nbsp;Bradford Moffat,&nbsp;David K. Wright,&nbsp;Travis L. Dutka,&nbsp;Julian Pepperell,&nbsp;Caroline C. Kerr,&nbsp;Kara E. Yopak,&nbsp;Shaun P. Collin","doi":"10.1002/cne.70148","DOIUrl":"10.1002/cne.70148","url":null,"abstract":"<p>A quantitative comparison of the absolute and relative volumes of different brain areas is useful for predicting the sensory capabilities and behavior of large pelagic teleosts, which are difficult to study in the field or in vivo. However, the size of pelagic teleost brain regions has only been approximated using the idealized ellipsoid method, which is susceptible to over- or underestimation, as it assumes the shape of brain regions to be an idealized ellipsoid or half-ellipsoid. This study examines the gross morphology and volumes of different sensory brain areas of southern bluefin tuna <i>Thunnus maccoyii</i> using magnetic resonance imaging (MRI). The results show that the optic tectum (568 ± 11 mm³) has a larger absolute volume compared to the olfactory bulb (50 ± 5 mm³), eminentia granularis (62 ± 9 mm³), and cristae cerebelli (47 ± 3 mm³), suggesting the significance of vision for <i>T. maccoyii</i>. The full segmentation of a <i>T. maccoyii</i> brain allowed the quantification of the integration areas, which reveals that the corpus cerebelli (1299 mm³) occupies the largest proportion (35%) of total brain volume, whereas the optic tectum only occupies 15% of total brain volume. The corpus cerebelli also exhibits a rostro-caudal elongation with multiple horizontal sulci, which resemble the corpus cerebelli of some species of sharks. The results reveal that the brain of <i>T. maccoyii</i> is dominated by the locomotive area of the corpus cerebelli and highlight the benefits of using MRI when performing quantitative analyses on the brain volumes of large pelagic teleosts.</p>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 4","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13023358/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147529772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Connectivity of the Superior Temporal Polysensory Area With the Presubiculum, Parasubiculum, Entorhinal Cortex, and Claustrum–Endopiriform Complex in the Common Marmoset (Callithrix jacchus)","authors":"Yoshiko Honda,&nbsp;Keiko Moriya-Ito,&nbsp;Nanako Hashimoto,&nbsp;Yasushi Kobayashi","doi":"10.1002/cne.70151","DOIUrl":"10.1002/cne.70151","url":null,"abstract":"<p>The rodent hippocampal–presubicular–entorhinal circuit is thought to be a key part of the circuitry involved in memory formation. In primates, additional connections are believed to enable more complex and higher-order memory information processing. We investigated whether such additional connections exist in the cortical regions adjacent to the hippocampal formation using a tracer injection method. We discovered that the marmoset parasubiculum (ParS), presubiculum (PreS) (distal portion), and entorhinal cortex (EC) (proximal or medial portion) have strong reciprocal connections with the superior temporal polysensory area (STP), which is known as a well-developed brain region in primates and where projections from diverse sensory areas converge. When the cholera toxin B subunit (CTB), a bidirectional tracer, was injected into various portions of ParS, PreS, and EC in one hemisphere, anterograde and retrograde labeling were observed in STP in both hemispheres. When CTB was injected into STP on one side, many retrogradely labeled cells were observed in layers III–V of ParS on the same side as the injection, and anterogradely labeled axons and terminal boutons were observed in layers I–III and V of ParS on both sides. In the distal portion of PreS and proximal portion of EC that were adjacent to ParS, retrogradely labeled cells were mostly observed in layer V, and substantial anterograde labeling was observed in all layers. Both in cases of STP injection and PreS (distal)-ParS-EC (proximal) injection, substantial anterograde and retrograde labeling were found in the claustrum–endopiriform complex (Cl–En). These results suggest the existence of a neural circuit that reciprocally connects STP, Cl–En, and PreS-ParS-EC, and may support functions such as higher-order multisensory memory consolidation.</p>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13014218/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147512516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Ovine Brain as a Model for Human Neurodevelopment: Immunohistochemical Profiling of Brain Maturation Markers in Preterm Lambs","authors":"Yoann Rodriguez,&nbsp;Anne Leostic,&nbsp;Olivier Le Coz,&nbsp;Vincent Mauffré,&nbsp;Joanne Fortemps,&nbsp;Lucile Cavarec,&nbsp;Fabienne Constant,&nbsp;Marine Denis,&nbsp;Paul Berveiller,&nbsp;Aude Tessier,&nbsp;Olivier Sandra,&nbsp;Leslie Schwendimann,&nbsp;Pierre Gressens,&nbsp;François Vialard,&nbsp;Emmanuelle Motte-Signoret MD, PhD","doi":"10.1002/cne.70149","DOIUrl":"10.1002/cne.70149","url":null,"abstract":"<p>Preterm birth is known to severely impact the neurological development of newborns with long-lasting complications and higher risks of neurological disorders. Sheep (<i>Ovis aries</i>) is well known as a pre-clinical model in therapeutic studies, such as extra-uterine support. The aim of our study was to investigate the relevance of the lamb as a pre-clinical model for preterm birth when cortical maturation of preterm and term lamb is addressed. Cesarean sections were performed on time-dated pregnant ewes to obtain 13 lambs at 100 days and 140 days of pregnancy each (corresponding to 24 and 36 weeks of pregnancy in humans, respectively). Brains were collected and separated in frontal lobe, temporo-parietal lobe, occipital lobe, and cerebellum. Immunohistochemistry staining was used for each brain area by targeting neurons, interneurons, synaptic vesicles, oligodendrocytes, myelin, astrocytes, and microglia. Quantifications were normalized by the surface area of analysis. Overall, 140-days late preterm lambs have significantly higher mean positivity for interneurons, synaptic vesicles, oligodendrocytes, astrocytes, and myelin than 100-days extremely preterm lambs. Similarly, significantly higher mean positivity for neurons was found in the cerebellum of 140-days term lambs. No significant difference was observed regarding microglia. Based on the cellular and structural markers used in this study, brain development in lamb seems to follow an antero–posterior direction similarly to what was reported in humans. Further studies with more specific markers and in-depth analysis will allow for a more accurate and exhaustive description of brain development in lamb.</p>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13010130/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147504183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Localization of Puncta Adherentia Junctions at GABAergic Synapses on Parvalbumin-Positive GABAergic Inhibitory Neurons in the Mouse Hippocampus","authors":"Kimitaka Katanazaka,&nbsp;Hajime Shiotani,&nbsp;Muneaki Miyata,&nbsp;Takeshi Kameyama,&nbsp;Shin Kedashiro,&nbsp;Ryouhei Komaki,&nbsp;Shota Nishii,&nbsp;Yutaro Kashiwagi,&nbsp;Yuka Sato,&nbsp;Shigeo Okabe,&nbsp;Norio Chihara,&nbsp;Riki Matsumoto,&nbsp;Kiyohito Mizutani,&nbsp;Yoshimi Takai","doi":"10.1002/cne.70152","DOIUrl":"10.1002/cne.70152","url":null,"abstract":"<p>Puncta adherentia junctions (PAJs) have been observed at glutamatergic excitatory synapses on glutamatergic excitatory neurons (<i>E</i>→<i>E</i> synapses) in the mouse hippocampus and are considered to be the mechanical adhesion sites between axon terminals and dendritic shafts. However, it remains unclear whether they are present at other types of synapses, such as glutamatergic synapses on GABAergic inhibitory neurons (<i>E</i>→<i>I</i> synapses) and GABAergic synapses on excitatory neurons (<i>I</i>→<i>E</i> synapses) and inhibitory neurons (<i>I</i>→<i>I</i> synapses). We showed here that the PAJ components, such as nectin-1, nectin-3, l-afadin, N-cadherin, β-catenin, and αN-catenin, were observed at all four types of synapses in cultured mouse hippocampal neurons. In the adult mouse hippocampus, these PAJ components were observed at a subset of <i>I</i>→<i>I</i> synapses on parvalbumin-positive GABAergic inhibitory neurons, similarly to their presence at <i>E</i>→<i>E</i> synapses in the CA1 and CA3 regions. In contrast, several PAJ components, including nectin-3, l-afadin, N-cadherin, β-catenin, and αN-catenin, were observed at <i>E</i>→<i>I</i> and <i>I</i>→<i>E</i> synapses, whereas nectin-1 was absent. These results indicate that the PAJs are formed at a subset of <i>I</i>→<i>I</i> synapses in addition to <i>E</i>→<i>E</i> synapses, where all examined PAJ components are present, whereas <i>E</i>→<i>I</i> and <i>I</i>→<i>E</i> synapses exhibit only partial localization of these components, reflecting molecular diversity among different synapses in the adult mouse hippocampus.</p>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cne.70152","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147486199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Do Subsets of Widefield Vertical Cells Exist in the Mouse Superior Colliculus?","authors":"N. Naeem,&nbsp;A. S. Slusarczyk,&nbsp;M. E. Bickford","doi":"10.1002/cne.70147","DOIUrl":"10.1002/cne.70147","url":null,"abstract":"<div>\u0000 \u0000 <p>Projections from widefield vertical (WFV) cells of the superior colliculus to the pulvinar nucleus form a conserved pathway for motion detection across mammalian species. While subtypes of tectopulvinar cells have been identified in the ground squirrel, it is unclear whether subtypes can be identified in mice. Using viral tracing, immunohistochemistry, and confocal and electron microscopy in Tac1, Ntsr1-GN209, and C57BL/6J mice, we attempted to characterize WFV cells based on their morphology, pulvinar projection patterns, expression of substance P, parvalbumin, or hyperpolarization-activated cation channels (HCN1), and their retinal innervation. We found that the Ntsr1-GN209 line labels a subset of tectopulvinar cells that lack parvalbumin but express HCN1. Furthermore, comparison of previous ultrastructural datasets revealed that Ntsr1-GN209 WFV cells innervate the pulvinar with synaptic terminals that are smaller than the overall population of tectopulvinar terminals. However, using retrograde, anterograde, and transsynaptic viral tracing, we found that in all three mouse lines, WFV cells could not be subdivided based on their dendritic arbors or projections to the lateral pulvinar (Pl) or caudal medial pulvinar (Pcm). We also found that a subset of WFV cells receive ipsilateral retinal input, but these cells did not differentially innervate the Pl or Pcm. Finally, we found that the retina provides one-third of the synaptic input to Ntsr1-GN209 WFV cells and primarily innervates their small distal dendrites. Together, our data indicate that although the Ntsr1-GN209 line labels a subset, the overall population of mouse WFV cells cannot be subdivided based on features identified in the ground squirrel.</p>\u0000 </div>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147473903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to “Dopaminergic Central Neurons and Peripheral Sensory Systems in Pteropod and Nudibranch Molluscs”","authors":"","doi":"10.1002/cne.70150","DOIUrl":"10.1002/cne.70150","url":null,"abstract":"<p>Norekian, T.P. and Moroz, L.L. (2025). “Dopaminergic Central Neurons and Peripheral Sensory Systems in Pteropod and Nudibranch Molluscs.” J Comp Neurol, 533: e70054. https://doi.org/10.1002/cne.70054</p><p>Originally, we suggested in the Discussion that the sensory neurons described here by TH immunoreactivity and their bipolar morphology are probably located also in the esophagus of <i>Clione</i> based on the previously published work by Kabotyanskii and Sakharov (1990), which used glyoxylate-induced histofluorescence method to identify catecholamine-containing neurons. However, this suggestion turned out to be incorrect. Our subsequent experiments with TH immunoreactivity (<i>N</i> = 7) showed no TH-ir neurons in the esophagus of <i>Clione</i>. These results, together with the fact that very thin walls of the esophagus are unlikely to support such elongated bipolar sensory neurons found in the thick outside cuticula, demonstrate that even though glyoxylate method could label some cells in the esophagus, they would be very different from the sensory neurons that we describe here.</p>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cne.70150","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147468142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing Trigeminal Nerve Branches in Lampreys and Gnathostomes Reveals Evolutionary Changes in Vertebrate Oral Nerve Innervation","authors":"Yuki Nakanishi,&nbsp;Motoki Tamura,&nbsp;Fumiaki Sugahara,&nbsp;Nono Kawada,&nbsp;Ryota Ishikawa,&nbsp;Saori Yamakami,&nbsp;Aki Maruyama-Watanabe,&nbsp;Juan Pascual-Anaya,&nbsp;Shigehiro Kuraku,&nbsp;Takashi Saitou,&nbsp;Makiko Fukui,&nbsp;Hiromichi Koyama,&nbsp;Shigeru Kuratani,&nbsp;Filippo M. Rijli,&nbsp;Daichi G. Suzuki,&nbsp;Yasunori Murakami","doi":"10.1002/cne.70145","DOIUrl":"10.1002/cne.70145","url":null,"abstract":"<div>\u0000 \u0000 <p>The trigeminal nerve consists of three major branches or rami (r) in jawed vertebrates: the ophthalmic (rV₁), maxillary (rV₂), and mandibular (rV₃), with rV₂ and rV₃ innervating the upper and lower jaws, respectively. This three-branch configuration is conserved in the lamprey, a representative of the cyclostomes, the sole survivor of jawless vertebrates. While the first branch is widely accepted to be homologous to that of jawed vertebrate rV₁, the homology of the other two remains unclear, so they are called rV₁, rV_2/3A, and rV_2/3B. In this study, we investigate evolutionary modifications of the trigeminal nerve by comparing its organization in lamprey and jawed vertebrate embryos. By detailed neuronal tracing analysis of rV_2/3B, which innervates the velum, we demonstrate that it consists solely of motor components. Conversely, we identify both sensory and motor fibers in rV_2/3A. These results make a striking contrast to the trigeminal nerve of the jawed vertebrates, as their rV₂ is purely sensory, but rV₃ is a mixed nerve. Furthermore, through comparative analyses of sensory projection inside the brain, we clarify that the principal sensory nucleus of the trigeminal nerve (PrV) of anamniotes (shark, catfish, and <i>Xenopus</i>) lacks a somatotopic organization, suggesting that somatotopy evolved in at least the last common ancestor of amniotes. Last, by gene expression analysis of <i>Drg11</i>, a marker for the PrV and the spinal trigeminal nucleus (SpV), we show that a PrV-equivalent region is not present in the lamprey. These findings indicate significant structural changes in the trigeminal nerve associated with jaw acquisition, including shifts in innervation territories, the disappearance of the branch innervating the velum, and the emergence of novel brain nuclei.</p>\u0000 </div>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147463369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Anatomy of GLP-1 Signaling in the Human Nodose Ganglion","authors":"Matthew R. Sapio,&nbsp;Andrew J Mannes","doi":"10.1002/cne.70146","DOIUrl":"10.1002/cne.70146","url":null,"abstract":"<div>\u0000 \u0000 <p>In this issue of <i>The Journal of Comparative Neurology</i>, Merchant et al. (2026) present comparative data defining glucagon-like peptide 1 receptor (GLP1R) expression in the mouse and human nodose ganglion, illuminating the molecular anatomy of the peripheral sensory targets of GLP-1 agonists.</p>\u0000 </div>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147433184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unexpected Evolutionary Divergence of Tachykinin-Positive Neurons Innervating the Central Complex in Hexapods","authors":"Uwe Homberg,&nbsp;Jing Xu,&nbsp;Tim Keyser,&nbsp;Fedor Suzdalenkov,&nbsp;Fabian Wimmer,&nbsp;Martina Fromandi,&nbsp;Stefano Bianco,&nbsp;Michelle Tez,&nbsp;Stefan Dippel","doi":"10.1002/cne.70142","DOIUrl":"10.1002/cne.70142","url":null,"abstract":"<p>The central complex comprises an assemblage of midline-spanning neuropils in the brain of insects that play a key role in goal-directed orientation and navigation vector calculation. The central complex consists of layers of tangential input neurons that contact topographically organized columnar neurons which provide outputs to the right and left brain hemispheres. Its anatomical organization and functional role are regarded as highly conserved across insects. In addition to classical neurotransmitters, a wide range of neuropeptides have been detected in the central complex including peptides of the tachykinin family. Because the cellular identity of tachykinin-containing neurons in the central complex has not been determined in most cases, we used antisera against tachykinin I and II from the migratory locust, termed Lom-TKs, to identify the immunolabeled neurons in hexapods ranging from flightless two-pronged bristletails to flies. The data show that LomTK-related peptides are present in the central complex of all studied species except crickets. In most species one or several types of columnar neurons were immunolabeled, sometimes together with certain subsystems of tangential input neurons. The types of immunolabeled columnar neurons, however, are distinctly different between species from different orders, in some cases even between insects within the same order, and comprise cell types that innervate either the upper or lower division of the central body. This high degree of evolutionary divergence of tachykinin-positive neurons, even in closely related groups, may be related to species-specific differences in navigational requirements and calls for caution with respect to homologizing neurons across clades.</p>","PeriodicalId":15552,"journal":{"name":"Journal of Comparative Neurology","volume":"534 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12933162/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147283835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}