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1.
BMC Health Serv Res ; 24(1): 59, 2024 Jan 11.
Article in English | MEDLINE | ID: mdl-38212779

ABSTRACT

BACKGROUND: A Meningitis and Encephalitis Surveillance (MERIN) was implemented in 2003 in Lower Saxony, Germany as an alternative to acute flaccid paralyses surveillance, as the latter did not reach WHO sensitivity criteria. The system provides information on circulating enterovirus (EV) serotypes by focussing on patients with suspected aseptic meningitis, encephalitis or acute flaccid paralysis and contributes to the national surveillance in documenting polio free status. MERIN is based on voluntary participation of hospitals. Therefore, our evaluation focusses on acceptability of the system's objectives and performance, and identifying areas for improvement. METHODS: To assess acceptability, 32 contributing hospitals were invited to an online-based survey (11/2021 to 01/2022) to rate the MERIN objectives, laboratory's performance, their workload, modes of processes and communication. Ideas for improvement were collected in open fields. In addition, data completeness and timeliness of laboratory diagnostics were assessed. RESULTS: Of 32 hospitals, 21 responded (66% response rate), sending 30 questionnaires, 25 from pediatric and 5 from neurological departments. High levels of satisfaction with the communication (≥ 96%), timeliness (≥ 81%), and distribution of the results (≥ 85%) were reported, 97% of participants judged the required workload as adequate. The median proportion of eligible patients included in MERIN was 75%. Participants gave rapid and reliable diagnostic testing the highest priority (96%), while monitoring of Germany's polio-free status was rated the lowest (61%). Providing medical reports digitally as well as regular updates about circulating EV serotypes were identified as areas for improvement. Data completeness of selected variables ranged from 78.3 to 99.9%. Median time between sample collection and arrival at laboratory was 2 days [IQR 1-3], EV diagnostics via PCR took one day [IQR 0-6] and EV isolation on cell culture 11 days [IQR 10-13]. CONCLUSION: MERIN is a highly accepted surveillance system. Its quality was enhanced further by addressing the suggested improvements such as regular reports on circulating EV serotypes and facilitating digital access to laboratory results. Our results emphasise the importance of recognizing and considering participants' motivations and expectations, and addressing their priorities, even if this is not the surveillance system's main focus. This approach can be applied to surveillance systems of other non-mandatory notifiable diseases.


Subject(s)
Encephalitis , Enterovirus Infections , Enterovirus , Meningitis , Poliomyelitis , Humans , Child , Enterovirus Infections/diagnosis , Enterovirus Infections/epidemiology , Meningitis/diagnosis , Meningitis/epidemiology , Poliomyelitis/epidemiology , Encephalitis/epidemiology , Germany/epidemiology , Surveys and Questionnaires , Population Surveillance/methods
2.
Epidemiol Infect ; 151: e70, 2023 04 05.
Article in English | MEDLINE | ID: mdl-37017135

ABSTRACT

We explored the feasibility, suitability, and reliability of using controls recruited among members of a non-probabilistic online panel ('panel controls') in a case-control study (CCS) to investigate a Salmonella Braenderup outbreak in Germany. For comparison, another control group was recruited via random digit dialling ('classical controls'). Panel members received questionnaires by email; classical controls were interviewed by phone. Both control groups were frequency-matched to cases by age and sex; the classical controls also by federal state. Cases and controls were queried mainly about fruit consumption since melons were the suspected infection vehicle. We calculated adjusted odds ratios (aOR) and 95% confidence intervals (CIs) using single-variable and multivariable logistic regression. The study included 32 cases, 81 panel controls and 110 classical controls. Analyses identified melons, particularly Galia melons, as the most likely infection vehicle using either control group (panel controls - aOR 12, CI 2.7-66; classical controls - aOR 55, CI 8-1100). Recruitment of panel versus classical controls required substantially less person-time (8 vs. 111 hours) and was about 10 times less expensive. We recommend this timely and reliable control recruitment method when investigating diffuse foodborne outbreaks with CCS.


Subject(s)
Disease Outbreaks , Salmonella Infections , Salmonella , Humans , Case-Control Studies , Germany/epidemiology , Reproducibility of Results , Surveys and Questionnaires , Salmonella Infections/epidemiology
3.
Cancer Epidemiol Biomarkers Prev ; 24(3): 538-45, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25542829

ABSTRACT

BACKGROUND: Chronic lymphocytic leukemia (CLL) is a chronic disease that often progresses slowly from a precursor stage, monoclonal B-cell lymphocytosis (MBL), and that can remain undiagnosed for a long time. METHODS: Within the European Prospective Investigation into Cancer cohort, we measured prediagnostic plasma sCD23 for 179 individuals who eventually were diagnosed with CLL and an equal number of matched control subjects who remained free of cancer. RESULTS: In a very large proportion of CLL patients' plasma sCD23 was clearly elevated 7 or more years before diagnosis. Considering sCD23 as a disease predictor, the area under the ROC curve (AUROC) was 0.95 [95% confidence interval (CI), 0.90-1.00] for CLL diagnosed within 0.1 to 2.7 years after blood measurement, 0.90 (95% CI, 0.86-0.95) for diagnosis within 2.8 to 7.3 years, and 0.76 (95% CI, 0.65-0.86) for CLL diagnosed between 7.4 and 12.5 years. Even at a 7.4-year and longer time interval, elevated plasma sCD23 could predict a later clinical diagnosis of CLL with 100% specificity at >45% sensitivity. CONCLUSIONS: Our findings provide unique documentation for the very long latency times during which measurable B-cell lymphoproliferative disorder exists before the clinical manifestation of CLL. IMPACT: Our findings have relevance for the interpretation of prospective epidemiologic studies on the causes of CLL in terms of reverse causation bias. The lag times indicate a time frame within which an early detection of CLL would be theoretically possible. Cancer Epidemiol Biomarkers Prev; 24(3); 538-45. ©2014 AACR.


Subject(s)
Biomarkers, Tumor/blood , Leukemia, Lymphocytic, Chronic, B-Cell/blood , Lymphoproliferative Disorders/blood , Receptors, IgE/blood , Adult , Aged , Case-Control Studies , Cohort Studies , Female , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis , Lymphoproliferative Disorders/diagnosis , Male , Middle Aged , Prognosis , Prospective Studies , Time Factors
4.
Carcinogenesis ; 35(12): 2716-22, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25269801

ABSTRACT

Previous epidemiological studies suggest an inverse association between allergies, marked by elevated immunoglobulin (Ig) E levels, and non-Hodgkin lymphoma (NHL) risk. The evidence, however, is inconsistent and prospective data are sparse. We examined the association between prediagnostic total (low: <20; intermediate: 20-100; high >100 kU/l) and specific IgE (negative: <0.35; positive ≥0.35 kU/I) concentrations against inhalant antigens and lymphoma risk in a study nested within the European Prospective Investigation into Cancer and Nutrition cohort. A total of 1021 incident cases and matched controls of NHL, multiple myeloma (MM) and Hodgkin lymphoma with a mean follow-up time of 7 years were investigated. Multivariate-adjusted odds ratios (ORs) with 95% confidence intervals (CI) were calculated by conditional logistic regression. Specific IgE was not associated with the risk of MM, B-cell NHL and B-cell NHL subtypes. In contrast, total IgE levels were inversely associated with the risk of MM [high level: OR = 0.40 (95% CI = 0.21-0.79)] and B-cell NHL [intermediate level: OR = 0.68 (95% CI = 0.53-0.88); high level: OR = 0.62 (95% CI = 0.44-0.86)], largely on the basis of a strong inverse association with chronic lymphocytic leukemia [CLL; intermediate level: OR = 0.49 (95% CI = 0.30-0.80); high level: OR = 0.13 (95% CI = 0.05-0.35)] risk. The inverse relationship for CLL remained significant for those diagnosed 5 years after baseline. The findings of this large prospective study demonstrated significantly lower prediagnostic total IgE levels among CLL and MM cases compared with matched controls. This corresponds to the clinical immunodeficiency state often observed in CLL patients prior to diagnosis. No support for an inverse association between prediagnostic levels of specific IgE and NHL risk was found.


Subject(s)
Biomarkers, Tumor/blood , Immunoglobulin E/blood , Leukemia, Lymphocytic, Chronic, B-Cell/epidemiology , Lymphoma/epidemiology , Multiple Myeloma/epidemiology , Adult , Aged , B-Lymphocytes , Case-Control Studies , Female , Follow-Up Studies , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/blood , Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , Lymphoma/blood , Lymphoma/diagnosis , Lymphoma/immunology , Male , Middle Aged , Multiple Myeloma/blood , Multiple Myeloma/diagnosis , Multiple Myeloma/immunology , Prognosis , Prospective Studies , Risk Factors
5.
Eur J Epidemiol ; 29(8): 585-94, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24859820

ABSTRACT

Lower respiratory tract infections (LRTIs) are a major cause of hospitalization in infants. Research suggests that immunomodulatory properties of vitamin D may influence LRTI risk. This study's objective was to examine whether 25-hydroxyvitamin D [25(OH)D] concentrations in cord blood influenced susceptibility to LRTI in the first year of life. Data was analyzed from a prospective birth cohort of 777 mother-infant pairs based in Ulm, Germany. Relative risks (RRs) of LRTI in relation to 25(OH)D cord blood levels were estimated by log-binomial regression after adjustment for potential confounders. To account for seasonal variation in both vitamin D levels and infections, we examined the association in different seasons. Analyses were conducted using clinical predefined cutpoints, quartiles, and season-standardized 25(OH)D quartiles. We observed a statistically significant association between 25(OH)D status in cord blood and risk of LRTI across the year using clinical cutpoints. The adjusted RR of LRTI for individuals with vitamin D deficiency (<25 nmol/L) in comparison to the referent category (>50 nmol/L) was 1.32 [95 % confidence interval (CI) 1.00, 1.73]. The association differed by maternal allergy status; children born to mothers without allergy demonstrated a RR of 1.45 (95 % CI 1.03, 2.03). The effect was largely driven by a strong association between 25(OH)D and LRTI in infants born in fall with a RR of 3.07 (95 % CI 1.37, 6.87). Our findings suggest that vitamin D deficiency at birth is associated with increased risk of LRTI particularly in infants born to mothers without allergy. The association seems strongest in infants born in fall.


Subject(s)
Fetal Blood , Respiratory Tract Infections/epidemiology , Vitamin D/analogs & derivatives , Vitamins/blood , Child , Child, Preschool , Female , Germany/epidemiology , Humans , Immunoenzyme Techniques , Infant , Logistic Models , Male , Mothers , Population Surveillance , Prevalence , Prospective Studies , Respiratory Tract Infections/blood , Risk Factors , Seasons , Vitamin D/blood , Vitamin D/metabolism , Vitamin D Deficiency/blood , Vitamins/metabolism
6.
Acta Neurobiol Exp (Wars) ; 73(2): 260-79, 2013.
Article in English | MEDLINE | ID: mdl-23823987

ABSTRACT

Calbindin-D28k (CB), parvalbumin (PV) and calretinin (CR) are calcium-binding proteins (CaBPs) considered to be markers for certain subpopulations of neurons in the central nervous system. The aim of this study was to describe the pattern of distribution of CB-, PV- and CR-immunoreactive elements in the rabbit corticomedial amygdaloid complex during the postnatal period. The time course of changes in CaBPs expression during maturation of the selected nuclei indicates their diversity. During the first month after birth, CaBPs expression stabilizes earliest in the anterior cortical and then in the medial nuclei. Later, during the second month of postnatal life, the posteromedial and posterolateral cortical nuclei maturate. The central nucleus requires a considerably longer time to reach maturity - about three months are needed to stabilize CaBPs expression in all its subdivisions. This nucleus also shows the most differentiated, time-dependent distribution of CaBPs immunoreactivity (especially CB), distinct in its divisions. The differences in the CaBPs immunoreactivity confirm previous reports concerning dissimilar origin and development, and also reflect the diversity of connectivity of the amygdaloid body - the collection of nuclei, considered as one functional integrity.


Subject(s)
Amygdala , Calbindin 1/metabolism , Calcium-Binding Proteins/metabolism , Parvalbumins/metabolism , Age Factors , Amygdala/cytology , Amygdala/growth & development , Amygdala/metabolism , Animals , Animals, Newborn , Calbindin 2/metabolism , Male , Neuroglia/metabolism , Neurons/metabolism , Rabbits
7.
Am J Clin Nutr ; 98(3): 827-38, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23885049

ABSTRACT

BACKGROUND: The relation between vitamin D status and lymphoma risk is inconclusive. OBJECTIVE: We examined the association between prediagnostic plasma 25-hydroxyvitamin D [25(OH)D] and lymphoid cancer risk. DESIGN: We conducted a study nested within the European Prospective Investigation into Cancer and Nutrition cohort of 1127 lymphoma cases and 1127 matched controls with a mean follow-up time of 7.1 y. Conditional logistic regression was used to estimate multivariable-adjusted incidence rate ratios of lymphoma risk in relation to plasma 25(OH)D. Season-standardized and season-specific 25(OH)D quartiles were used. We also analyzed 25(OH)D as a continuous variable and used predefined cutoffs. RESULTS: No statistically significant association between plasma 25(OH)D and overall lymphoid cancer risk was observed. A positive association for B-cell non-Hodgkin lymphoma was noted only in those with a diagnosis made during the first 2 y of follow-up (P-heterogeneity = 0.03), which suggests the possibility of reverse causality. Further analysis restricted to participants with ≥2 y of follow-up time showed a significant association between 25(OH)D and chronic lymphocytic leukemia (CLL) (n = 161): adjusted incidence rate ratios were 0.40 (95% CI: 0.18, 0.90; P-trend = 0.05) and 0.31 (95% CI: 0.13, 0.76; P-trend = 0.03) for the top compared with the bottom season-standardized and season-specific quartiles, respectively. Data on dietary vitamin D intake provided further support for the observed association (incidence rate ratio: 0.33; 95% CI = 0.12, 0.89; P-trend = 0.006). CONCLUSIONS: Our findings do not support a protective role of high 25(OH)D concentration in lymphoid cancers overall. However, they suggest that higher concentrations of 25(OH)D are associated with a reduced risk of CLL.


Subject(s)
Leukemia, Lymphoid/prevention & control , Lymphoma, Non-Hodgkin/etiology , Lymphoma/etiology , Vitamin D/analogs & derivatives , Case-Control Studies , Chronic Disease , Cohort Studies , Diet , Female , Follow-Up Studies , Humans , Incidence , Leukemia, Lymphoid/blood , Leukemia, Lymphoid/etiology , Logistic Models , Lymphoma/blood , Lymphoma, Non-Hodgkin/blood , Male , Middle Aged , Vitamin D/blood , Vitamin D/therapeutic use
8.
Brain Res ; 996(1): 97-110, 2004 Jan 16.
Article in English | MEDLINE | ID: mdl-14670636

ABSTRACT

The endopiriform nucleus, further divided into dorsal and ventral parts, and the neighbouring pre-endopiriform (pEn) nucleus form a region of highly heterogeneous structure involved in numerous physiological and pathological processes. Nonpyramidal neurons of this region containing three neuropeptides-somatostatin (SOM), neuropeptide Y (NPY), and vasoactive intestinal peptide (VIP)-were examined in this study. Their colocalization with three calcium-binding proteins-parvalbumin (PV), calbindin D28k (CB), calretinin (CR), and with nitric oxide synthase (NOS), was investigated by qualitative and quantitative methods. The results are summarized as follows: (1) all studied substances are distributed in neurons of the entire region, (2) SOM-ir neurons constitute the most numerous neuropeptide-containing population, whereas NOS-ir neurons make up the largest population of all studied, (3) colocalizations are found in the endopiriform region (Enr) (SOM with CB, PV and NOS; VIP with CR; NPY with NOS and NOS with CR), (4) heterogeneity of the endopiriform region appears in the differences of cells' shape distributions of single-labeled (SOM-, CR-PV-ir) and double-labeled (SOM/CB-, SOM/PV-, NPY/NOS- and NOS/CR-ir) neurons, as well as in differentiated percentage values of SOM/NOS, NPY/NOS and VIP/CR double-labeled neurons in three studied parts; additionally, differences in distribution of immunoreactive neuropil elements between parts of the region are observed. Numerous regional differences concerning neuronal morphology and immunocytochemical characteristics justify further division of the endopiriform region into distinguished parts. Some immunocytochemical features of the neurons in studied region may contribute to the role in epileptogenesis.


Subject(s)
Calcium-Binding Proteins/metabolism , Cerebral Cortex/cytology , Neurons/metabolism , Neuropeptides/metabolism , Nitric Oxide Synthase/metabolism , Animals , Cell Count , Cell Size , Female , Immunohistochemistry/methods , Male , Neurons/classification , Rats
9.
Folia Morphol (Warsz) ; 63(4): 367-72, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15712128

ABSTRACT

In our study we used c-Fos protein (as a marker of cellular activity) to identify whether cells containing parvalbumin (PV) in the piriform cortex (PC) are engaged in the response to stress stimulation and to discover how this expression changes during maturation. The material consisted of Wistar rats of postnatal (P) ages between 0 and 120 days divided into 9 groups: P0, P4, P7, P10, P14, P21, P30, P90, P120. Each group consisted of 5 experimental and 3 control animals. Rats of the experimental groups were exposed to the "open field test" throughout 10 minutes. The control animals were kept in a home cage. Our results showed that c-Fos activity in the open field test was observed in layers II and III of PC after birth. It then increased and stabilised on P30. In the second week of life PV-positive cells were also observed in those layers. These achieved maturity in the 4th week of life. After this time basket-like structures appeared but the level of PV/c-Fos co-localisation was low. Only small differences were observed between the anterior and posterior parts of PC. In the anterior part a higher number of PV-positive neurons, neuropil threads, and basket-like structures and a larger degree of PV/c-Fos co-localisation were observed. Our results suggested that during maturation PV cells are not directly activated in response to stress stimuli but PV neurons via their numerous endings influence the activation of c-Fos-positive cells predominantly in the anterior part of PC.


Subject(s)
Neurons/metabolism , Olfactory Pathways/cytology , Olfactory Pathways/growth & development , Parvalbumins/metabolism , Stress, Physiological/physiopathology , Animals , Exploratory Behavior/physiology , Olfactory Pathways/physiology , Rats , Rats, Wistar , Stress, Physiological/metabolism
10.
Folia Morphol (Warsz) ; 63(4): 381-5, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15712131

ABSTRACT

Our intention in the present study was to ascertain whether NO-producing cells in the basolateral complex (BLC) and paracapsular intercalated nerve cell groups (Ip) of the amygdala are activated in the open field (OF) test. The material consisted of 8 adult rat brains. The OF test was applied throughout 10 min and 90 min before the death of the animals. The brain sections were double stained using the antibodies against c-Fos (marker of neuronal activation) and against nitric oxide synthase (NOS -- marker of NO-producing cells). The neurons containing NOS and those revealing c-Fos activity constituted distinct populations within both the BLC and Ip but NOS-immunoreactive fibres often surrounded the c-Fos-immunoreactive neurons. Our results suggest that (1) neurons of the basolateral complex of the amygdala and paracapsular intercalated islands are involved but probably not crucial for the open field stress response and (2) NOS-immunoreactive cells in the BLC and Ip are not activated after OF exposure.


Subject(s)
Amygdala/cytology , Amygdala/physiology , Nerve Tissue Proteins/metabolism , Neurons/enzymology , Nitric Oxide Synthase/metabolism , Stress, Physiological/physiopathology , Animals , Exploratory Behavior/physiology , Nitric Oxide Synthase Type I , Proto-Oncogene Proteins c-fos/metabolism , Rats , Rats, Wistar , Stress, Physiological/metabolism
11.
Folia Morphol (Warsz) ; 62(3): 171-4, 2003.
Article in English | MEDLINE | ID: mdl-14507041

ABSTRACT

We examined the expression of brain nitric oxide synthase (bNOS) in two developing rat brain structures, the striatum and the cerebral cortex. For this purpose, we quantified the relative protein concentration level using the Western blotting method and densitometric scanning. 32 Wistar rats, divided according to survival period (PO-P120-postnatal days) were used in this study. Our results demonstrate that bNOS expression rises in these structures during the first week of postnatal life, reaching a maximum in the striatum on the 10th day and in the cerebral cortex on the 7th day of postnatal life. After the period of increase the expression declines and after the 14th day a stabilisation of bone protein concentration is observed, both in the striatum and the cerebral cortex. These changes in bone protein expression might be related to the important role of nitric oxide in the developing rat brain, especially in synaptogenesis, apoptosis and neurotransmission.


Subject(s)
Cerebral Cortex/enzymology , Cerebral Cortex/growth & development , Corpus Striatum/enzymology , Corpus Striatum/growth & development , Neurons/enzymology , Nitric Oxide Synthase/metabolism , Nitric Oxide/metabolism , Aging/metabolism , Animals , Animals, Newborn , Blotting, Western , Cerebral Cortex/cytology , Corpus Striatum/cytology , Neurons/cytology , Rats , Rats, Wistar , Up-Regulation/physiology
12.
Folia Morphol (Warsz) ; 62(3): 227-30, 2003.
Article in English | MEDLINE | ID: mdl-14507053

ABSTRACT

The aim of the present study is to follow topographical and morphological changes in the development of the amygdaloid basolateral complex (BLC) in the rabbit. The material consists of 35 brains of New Zealand rabbits of both sexes, divided into 7 age groups (P2-P90). In cresyl violet preparations BLC is already well visible on P2 and is composed of the lateral (divided into dorsolateral and ventromedial divisions), basolateral and homogenous basomedial nuclei. On about the 7th postnatal day it is possible to divide the basomedial nucleus (BM) into dorsal (Bmd) and ventral (BMv) divisions. The topography and subdivisions set on P7 are maintained in further periods of life. The morphology of neurons (shape, dendrites, staining) changes significantly until P21 in all BLC nuclei. Our results indicate that BLC achieves morphological maturity relatively late, which is probably connected with a long creation of emotional memory and regulation of emotional behaviour.


Subject(s)
Amygdala/cytology , Amygdala/growth & development , Cell Differentiation/physiology , Dendrites/ultrastructure , Neural Pathways/cytology , Neural Pathways/growth & development , Aging/physiology , Amygdala/physiology , Animals , Animals, Newborn , Cell Size/physiology , Dendrites/physiology , Emotions/physiology , Female , Male , Memory/physiology , Neural Pathways/physiology , Rabbits
13.
Folia Morphol (Warsz) ; 62(2): 75-87, 2003 May.
Article in English | MEDLINE | ID: mdl-12866666

ABSTRACT

The morphometric analysis of changes occurring in the rat and rabbit ventroposterolateral (VPL) nucleus of the thalamus during the postnatal development was performed using unbiased stereological methods. The materials used in the study included 30 Wistar rats and 32 New Zealand rabbits aged from P0 to P180 (P-postnatal day), which were divided into six and eight age groups, respectively. The following stereological parameters of VPL nucleus on the cresyl violet stained sections were determined: volume of the nucleus, numerical density and total number of neurons. The total number of neurons indicated that the development of VPL nucleus in both species ended within the third week of postnatal life. The volume of VPL nucleus increased gradually (by about 2.2 and 5 times in rats and rabbits, respectively) in comparison with the volume of the cerebral hemisphere during the development from P0 to adulthood. The numerical density of VPL neurons decreased rapidly at the beginning of postnatal life and stabilized by the end of the third week. In both species, the gradual increase in the volume of VPL nucleus and the simultaneous decrease in the neuronal density in the first week of postnatal life were mainly caused by changes in the neuropil volume. The total number of cells did not change remarkably during the first postnatal week. However, it decreased significantly during the second week. This decrease was probably due to the naturally occuring cell death. These results show that the most prominent qualitative and quantitative changes in VPL nucleus and its neurons occur during the first two weeks of postnatal life of rats and rabbits. Also, because the thalamocortical relay neurons completely acquire their physiological features, this the most critical period of time for their morphological maturation.


Subject(s)
Neurons/cytology , Ventral Thalamic Nuclei/cytology , Animals , Animals, Newborn , Cell Count , Cell Nucleus , Female , Male , Rabbits , Rats , Rats, Wistar , Species Specificity , Ventral Thalamic Nuclei/growth & development
14.
Folia Morphol (Warsz) ; 62(2): 129-32, 2003 May.
Article in English | MEDLINE | ID: mdl-12866673

ABSTRACT

A comparative quantitative study of the somatosensory thalamocortical connections in the rat and rabbit, labeled with the fluorescent retrograde tracer Fluoro-Gold (FG), was conducted by means of unbiased stereology. FG was injected into the primary somatosensory cortex of the rat and rabbit in different age groups from P0 to P180 (P-postnatal day). The numerical density of retrogradely labeled the ventroposterolateral (VPL) projection neurons was analyzed. A significant decrease in this parameter was observed during the first two weeks of postnatal life in both studied species. Changes of the neuropil volume and selective elimination of early cortical connections stemming from the VPL may possibly cause this process. A withdrawal of axon collaterals from the expanded cortical sites as well as apoptosis (existing both in the VPL and parietal cortex) contribute to a decrease in the numerical density. Our observations allow us to conclude that the thalamocortical somatosensory connections established before the birth undergo significant quantitative changes in both studied species during the first two weeks of postnatal life and this period seems to be crucial for maturation of the thalamocortical loop.


Subject(s)
Afferent Pathways/growth & development , Somatosensory Cortex/growth & development , Stilbamidines , Thalamus/growth & development , Afferent Pathways/metabolism , Animals , Animals, Newborn , Apoptosis , Axonal Transport/physiology , Cell Count , Fluorescent Dyes/administration & dosage , Fluorescent Dyes/analysis , Neurons/cytology , Neurons/metabolism , Rabbits , Rats , Rats, Wistar , Somatosensory Cortex/cytology , Somatosensory Cortex/metabolism , Species Specificity , Staining and Labeling , Thalamus/cytology , Thalamus/metabolism
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