RESUMO

Diabetes is a metabolic disorder resulting in long-term hyperglycemia that could induce oxidative stress as well as neural modifications in the central nervous system. Periodontal disease is highly comorbid with diabetes and in some cases, with exacerbated pain responses. Periodontal tissue is innervated by trigeminal afferents which extend to the nucleus oralis (NO) that sends input to the ventral posterior lateral thalamic nuclei (VPL). The present study aimed to evaluate the consequences of periodontitis, diabetes and both conditions on the dendritic morphology, spine type, and density in neurons of the NO and VPL in male and female rats. A quantitative neuromorphological analysis was performed using the Cox-Golgi staining in male and female rats in four groups: naïve control, after a periodontitis procedure, diabetic, and diabetic with periodontitis. Periodontitis decreased the total dendritic length (TDL) in the NO of the male rat but no change in the female rat and no neuronal alterations were observed in the VPL of both male and female rats. In contrast, diabetes increased the number of spines in the NO and VPL and decreased TDL in the NO in both male and female rats. We observed that periodontitis induced a dimorphic effect in the NO, whereas diabetes induced a strong neuromorphological effect regardless of sex. Moreover, while periodontitis had a limited effect on the neuronal morphology, it dramatically modified the neural consequences in the VPL and NO when comorbid with diabetes. In conclusion, these neuroplastic modifications may be relevant to understand how diabetes exacerbates the outcome of periodontitis in humans, particularly in the female population.

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RESUMO

Orofacial injuries often result in persistent pain and are therefore considered a common health problem worldwide. Considerable evidence suggests that peripheral sensory nerve injury results in diverse plastic changes in the central nervous system (CNS). Tooth pulp is innervated by trigeminal afferents which extend to the trigeminal brainstem sensory nuclear complex and send input to higher level neurons in the CNS, including the ventral posterolateral nucleus of the thalamus (VPL). In the present study, we examined the long term effects of pulpal injury on neuronal arborization in the VPL using morphological analysis via Golgi-Cox staining. In addition, we examined these effects in both male and female rats due to the major prevalence of oral pain in women. Quantitative morphological analysis revealed that pulpal injury induced neuronal hypertrophy in VPL neurons of female rats. In clear contrast, pulpal injury increased arborization close to the soma and reduced arborization distal to the soma without modification of total dendritic length in male rats. As a result, we show, for the first time, sex-dependent morphological alterations in VPL neurons after orofacial peripheral injury. Since dental injuries are readily reproducible in rat dental molars and closely mimic the clinical setting in humans, this model represents a useful tool to further understand mechanisms of orofacial pain.

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RESUMO

BACKGROUND: Matricaria Chamomilla L. (Mch), popularly known as chamomile, has been used for centuries as an herbolary remedy due to its broad clinical spectrum. The aim of this study was to evaluate the effect of Mch associated to a vehicle with emollient function in induced atopic dermatitis (AD)-like lesions in a murine model. METHODS: AD was induced with dinitrochlorobenzene on 12 male seven-week old BALB/c mice. Animals were divided in three groups (control, GC; control negative, GCN; and experimental, GE). Liquid petrolatum was applied to the GCN and liquid petrolatum with aqueous extract of Mch at 7% to the GE. Induction and evolution of the lesions were verified by biopsy at 2nd and 6th week. Evaluation of peripheral blood cells to correlate inflammatory cells was made as well at the same weeks. Lesions were clinically evaluated at 2nd, 4th and 6th week. Scratching was monitored according to the observation methodology of Kobayashi et al. RESULTS: Mch aqueous extract associated to a vehicle with emollient function improves atopic dermatitis-like lesions after two weeks.

INTRODUCCIÓN: Matricaria chamomilla L. (Mch), conocida popularmente como manzanilla, ha sido utilizada por cientos de años como remedio herbolario debido a su amplio espectro en cuanto a sus usos clínicos. El objetivo de este trabajo fue evaluar el efecto de Mch asociada a un vehículo con función emoliente como tratamiento de lesiones tipo-dermatitis atópica (DA) en un modelo murino. MÉTODOS: se indujo DA con dinitroclorobenceno a 12 ratones BALB/c macho de siete semanas de edad, divididos en tres grupos (control, GC; control negativo, GCN y; experimental, GE). Se aplicó petrolato líquido al GCN y petrolato líquido con extracto acuoso de Mch al 7% al GE durante cuatro semanas. La inducción y evolución de las lesiones se corroboraron por biopsia a las dos y seis semanas, analizando sangre periférica en búsqueda de células inflamatorias en los mismos tiempos. Las lesiones fueron evaluadas clínicamente a las dos, cuatro y seis semanas. El rascado se evaluó de acuerdo a la metodología de observación de Kobayashi et al. RESULTADOS: el extracto acuoso liofilizado de Mch asociado a un vehículo con función emoliente demostró mejoría del aspecto de las lesiones tipo DA después de dos semanas.

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