Microbiological quality and safety of minimally processed parsley (Petroselinum crispum) sold in food markets, southeastern Brazil.

AIMS: This study evaluated the microbiological quality and safety of minimally processed parsley sold in southeastern Brazilian food markets. METHODS AND RESULTS: One hundred samples were submitted to the enumeration of Enterobacteriaceae by plating on MacConkey agar. Colonies of Enterobacteriaceae were randomly selected and identified by MALDI-TOF MS. Samples were also tested for Listeria monocytogenes and Salmonella sp. The mean count of Enterobacteriaceae was 6·0 ± 1·0 log CFU per gram, while 18 genera (including 30 species) of bacteria belonging to this family were identified. Salmonella and L. monocytogenes were not detected, while L. innocua was found in two samples and L. fleischmannii was found in one sample. Moreover generic Escherichia coli was found in three samples, all from different brands of minimally processed parsley. CONCLUSIONS: Even though microbial pathogens were not isolated, a variety of indicator micro-organisms were identified, including vegetable spoilers and species capable of causing human opportunistic infections. These results suggest hygienic failures and/or lack of temperature control during processing and storage of these ready-to-eat products. SIGNIFICANCE AND IMPACT OF STUDY: This study highlights the need for control measures during the production chain of minimally processed parsley in order to reduce microbial contamination and the risks of foodborne diseases.

Assessment of the microbiological quality and safety of minimally processed vegetables sold in Piracicaba, SP, Brazil.

The present study shows the results of the microbiological quality and safety of minimally processed vegetables sold in supermarkets and grocery stores located in the city of Piracicaba, SP, Brazil. A total of 100 samples were collected and submitted to enumeration of total coliforms, coliforms at 45°C and generic Escherichia coli using the standard most probable number (MPN) method, in addition to enumeration of total Enterobacteriaceae by plating on MacConkey agar. Moreover, colonies of Enterobacteriaceae were randomly selected and submitted to identification on a MALDI-TOF MS Biotyper™. Samples were also tested for Salmonella spp. according to the ISO 6579:2002 method. The mean count of total coliforms was 2·9 ± 0·5 log MPN per g. For coliforms at 45°C, 20 samples were positive (mean 1·5 ± 1·0 log MPN per g). Generic E. coli was detected in 16 samples (mean 1·4 ± 0·9 log MPN per g) and only one was positive for Salmonella. The mean count of total Enterobacteriaceae was 6·5 ± 1·2 log CFU per g and the most frequent genera identified by MALDI-TOF were Enterobacter (25·9%), Pantoea (9·6%) and Rahnella (9·0%). Overall, results point to poor microbiological quality of a few samples, indicating hygiene failure during their processing. This can pose health risks to consumers, mainly because these products were labelled as sanitized and marketed as ready-to-eat. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, the microbiological quality and safety of minimally processed vegetables sold in the city of Piracicaba, SP, Brazil, were evaluated through the detection of Salmonella spp., generic Escherichia coli and other Enterobacteriaceae. The results obtained point to poor microbiological quality and safety of a few samples, as generic E. coli was detected in 16 out of 100 samples and Salmonella was isolated from one of them. This indicates hygiene failures during their processing and health risk to consumers, since these products are usually sold as ready-to-eat and typically require no further heat treatment before consumption.

Recurrent transient global amnesia after intracavernous Caverject injection in erectile dysfunction after robotic prostatectomy.

Treatment of erectile dysfunction after radical prostatectomy includes intracavernous Caverject injections. We present the case of recurrent transient global amnesia in a man performing self-administration of Caverject after robotic radical prostatectomy. The correlation between the intracavernous injection and the neurological phenomenon was repeated and evident, yet the specific aetiology of transient global amnesia remains uncertain.

Assessing the relationship between organic farming practices and microbiological characteristics of organic lettuce varieties (Lactuca sativa L.) grown in Sao Paulo, Brazil.

AIMS: This study aimed to gather information on farming practices employed in organic lettuce fields in Sao Paulo, Brazil and associate these practices with the microbiological characteristics of the products. METHODS AND RESULTS: Practices were surveyed using a questionnaire applied in ten farms, where 200 heads of lettuce were collected and submitted to enumeration of total coliforms and generic Escherichia coli and tested for Salmonella spp. using culture and molecular (qPCR) methods. Based on the responses, the farms could be clustered in two groups: group 1, comprised by six farms, where chicken manure was used as fertilizer in most of them and the composting process was not performed on site; and group 2, comprised by four farms, where other types of fertilizer were used, and the composting process was performed on site. Generic E. coli was detected in 56 (28%) samples, with an average of 1·1 ± 0·7 log MPN per g. Salmonella DNA was detected in two (1%) samples by qPCR. CONCLUSIONS: The prevalence and bacterial loads of generic E. coli, and the occurrence of Salmonella, even at low populations undetectable by conventional culture methods, highlight the need for control measures during farming practices to reduce microbial contamination and risks of foodborne illnesses. These measures include the use of properly composted manure and appropriate washing procedures for leafy vegetables before consumption. SIGNIFICANCE AND IMPACT OF THE STUDY: The obtained data contribute to a better understanding of the farming practices of organically grown lettuces in Sao Paulo, Brazil.

Should gentamicin trough levels be routinely obtained in term neonates?

OBJECTIVE: Gentamicin is a common antibiotic used to treat sepsis in neonates. We hypothesize that obtaining routine gentamicin trough levels may not be necessary in low-risk, term infants. STUDY DESIGN: We performed a retrospective cohort study of term infants (n=346) treated with gentamicin in a single level III neonatal intensive care unit (NICU). The results of gentamicin trough levels and the correlation with risk factors and potential side effects were recorded. In addition, we conducted a survey of 75 academic NICUs across the United States regarding their gentamicin monitoring practice. RESULTS: Routine trough levels did not predict potential gentamicin toxicity in neonates with low risk factors. Regression analysis demonstrated a positive correlation between gentamicin trough levels and serum creatinine. The survey of the NICUs in the United States demonstrated significant inconsistency in gentamicin monitoring practice. CONCLUSION: Obtaining gentamicin trough levels guided by risk factors is more appropriate than obtaining routine trough levels in low-risk term neonates.

Evaluation of a cross contamination model describing transfer of Salmonella spp. and Listeria monocytogenes during grinding of pork and beef.

In a previous study, a model was developed to describe the transfer and survival of Salmonella during grinding of pork (Møller, C.O.A., Nauta, M.J., Christensen, B.B., Dalgaard, P., Hansen, T.B., 2012. Modelling transfer of Salmonella typhimurium DT104 during simulation of grinding of pork. Journal of Applied Microbiology 112 (1), 90-98). The robustness of this model is now evaluated by studying its performance for predicting the transfer and survival of Salmonella spp. and Listeria monocytogenes during grinding of different types of meat (pork and beef), using two different grinders, different sizes and different numbers of pieces of meats to be ground. A total of 19 grinding trials were collected. Acceptable Simulation Zone (ASZ), visual inspection of the data, Quantitative Microbiological Risk Assessment (QMRA), as well as the Total Transfer Potential (TTP) were used as approaches to evaluate model performance and to access the quality of the cross contamination model predictions. Using the ASZ approach and considering that 70% of the observed counts have to be inside a defined acceptable zone of ±0.5 log10CFU per portion, it was found that the cross contamination parameters suggested by Møller et al. (2012) were not able to describe all 19 trials. However, for each of the collected grinding trials, the transfer event was well described when fitted to the model structure proposed by Møller et al. (2012). Parameter estimates obtained by fitting observed trials performed at different conditions, such as size and number of pieces of meat to be ground, may not be applied to describe cross contamination of unlike processing. Nevertheless, the risk estimates, as well as the TTP, revealed that the risk of disease may be reduced when the grinding of meat is performed in a grinder made of stainless steel (for all surfaces in contact with the meat), using a well-sharpened knife and holding at room temperatures lower than 4°C.

Assessing the effect of sodium dichloroisocyanurate concentration on transfer of Salmonella enterica serotype Typhimurium in wash water for production of minimally processed iceberg lettuce (Lactuca sativa L.).

UNLABELLED: This study evaluated the impact of sodium dichloroisocyanurate (5, 10, 20, 30, 40, 50 and 250 mg l(-1) ) in wash water on transfer of Salmonella Typhimurium from contaminated lettuce to wash water and then to other noncontaminated lettuces washed sequentially in the same water. Experiments were designed mimicking the conditions commonly seen in minimally processed vegetable (MPV) processing plants in Brazil. The scenarios were as follows: (1) Washing one inoculated lettuce portion in nonchlorinated water, followed by washing 10 noninoculated portions sequentially. (2) Washing one inoculated lettuce portion in chlorinated water followed by washing five noninoculated portions sequentially. (3) Washing five inoculated lettuce portions in chlorinated water sequentially, followed by washing five noninoculated portions sequentially. (4) Washing five noninoculated lettuce portions in chlorinated water sequentially, followed by washing five inoculated portions sequentially and then by washing five noninoculated portions sequentially in the same water. Salm. Typhimurium transfer from inoculated lettuce to wash water and further dissemination to noninoculated lettuces occurred when nonchlorinated water was used (scenario 1). When chlorinated water was used (scenarios 2, 3 and 4), no measurable Salm. Typhimurium transfer occurred if the sanitizer was ≥10 mg l(-1) . Use of sanitizers in correct concentrations is important to minimize the risk of microbial transfer during MPV washing. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, the impact of sodium dichloroisocyanurate in the wash water on transfer of Salmonella Typhimurium from inoculated lettuce to wash water and then to other noninoculated lettuces washed sequentially in the same water was evaluated. The use of chlorinated water, at concentration above 10 mg l(-1) , effectively prevented Salm. Typhimurium transfer under several different washing scenarios. Conversely, when nonchlorinated water was used, Salm. Typhimurium transfer occurred in up to at least 10 noninoculated batches of lettuce washed sequentially in the same water.

[New recommendations for contact tracing in tuberculosis]. / Neue Empfehlungen für die Umgebungsuntersuchungen bei Tuberkulose*1.

In 2007, the German Central Committee against Tuberculosis (DZK) published recommendations for contact tracing that introduced the new interferon gamma release assays (IGRAs). Meanwhile, substantial progress has been made in documenting the utility of IGRAs. Because IGRAs are usually superior to the tuberculin skin test (TST) in detecting latent TB infection (LTBI) with respect to sensitivity and specificity in adult contact populations that are at least partially BCG vaccinated, it is now recommended that instead of two-step testing only IGRAs be used.[nl]As the literature does not yet provide sufficient data on the accuracy of IGRAs in children younger than 5 years, the TST remains the method of choice in that age group. To date, also, no clear body of data exists to substantiate better performance for IGRAs than for the TST in older children, thus in this age group using of either test is recommended. The new recommendations also underscore the importance of a diligent preselection of close contacts in order to achieve a high probability that positive test results represent recent infection and to thus increase the benefit of chemopreventive treatment for those identified as requiring it. In a third point of update, it is noted that re-testing of contacts individuals found positive for LTBI may produce a considerable number of false-negative results and should thus be avoided in case of documented exposure.

[New recommendations for contact tracing in tuberculosis. German Central Committee against Tuberculosis]. / Neue Empfehlungen für die Umgebungsuntersuchungen bei Tuberkulose. Deutsches Zentralkomitee zur Bekämpfung der Tuberkulose.

In 2007, the German Central Committee against Tuberculosis (DZK) published recommendations for contact tracing that introduced the new interferon gamma release assays (IGRAs). Meanwhile, substantial progress has been made in documenting the utility of IGRAs. Because IGRAs are usually superior to the tuberculin skin test (TST) in detecting latent TB infection (LTBI) with respect to sensitivity and specificity in adult contact populations that are at least partially BCG vaccinated, it is now recommended that instead of two-step testing only IGRAs be used.[nl]As the literature does not yet provide sufficient data on the accuracy of IGRAs in children younger than 5 years, the TST remains the method of choice in that age group. To date, also, no clear body of data exists to substantiate better performance for IGRAs than for the TST in older children, thus in this age group using of either test is recommended. The new recommendations also underscore the importance of a diligent preselection of close contacts in order to achieve a high probability that positive test results represent recent infection and to thus increase the benefit of chemopreventive treatment for those identified as requiring it. In a third point of update, it is noted that re-testing of contacts individuals found positive for LTBI may produce a considerable number of false-negative results and should thus be avoided in case of documented exposure.

Protective antifungal yeast killer toxin-like antibodies.

After several years of controversy, antibodies (Abs) are now believed to play an important role in the protection against fungal infections. Among them, recent data are strongly supporting the relevance of protective yeast killer toxin-like Abs ("antibiobodies", KT-Abs), which are able to exert a direct microbicidal activity by mimicking a killer toxin (PaKT) and its interaction with cell wall receptors on susceptible cells essentially constituted by beta-glucans. This review will focus on the implications of the yeast killer phenomenon, and, particularly, the occurrence and antimicrobial activity of protective antifungal KT-Abs, such as those produced during the course of experimental and natural infections caused by PaKT-sensitive microorganisms or produced by idiotypic vaccination with a PaKT-neutralizing mAb. The strong therapeutic activity exerted against different experimental mucosal and systemic mycoses by monoclonal and recombinant microbicidal KT-Abs (either in their soluble forms or expressed on human commensal bacteria) as well as by a synthetic killer peptide (KP, an antibody fragment engineered from the sequence of a recombinant KT-Ab) will be discussed. The surprisingly wide antimicrobial spectrum of activity against eukaryotic and prokaryotic pathogenic agents, such as fungi, bacteria and protozoa, of these Abs and Ab-derived molecules suggests new potential strategies for transdisease anti-infective prevention and therapy.

Lesiones traumáticas contusas del abdómen: tratamiento no operatorio / Blunt abdominal trauma: nonoperative management

Antecedentes: Históricamente, las lesiones traumáticas del abdomen fueron tratados en forma quirúrgica. Pero desde un tiempo existe una tendencia creciente hacia el manejo no operatorio de estas lesiones, fundamentalmente en las correspondencias a los traumatismos por contusión. Objetivo: Analizar una serie de casos de lesiones traumáticas contusas del abdómen, a las que se les efectuó tratamiento no operatorio, para evaluar la efectividad del método. Lugar y aplicación: Servicios de Emergencias y de Cirugía General. Diseño: Estudio observacional retrospectivo basado en criterios básicos y descripción de hallazgos clínicos. Población: Muestra consecutiva de 60 casos de pacientes asistidos por presentar 65 lesiones traumáticas contusas del abdómen, tratados en forma no operatoria entre el 1/1/95 y el 15/11/04. Método: Se analizaron las historias clínicas de los pacientes de la población en estudio para determinar las diferentes lesiones tratadas; los criterios de inclusión utilizados, los métodos de estudio efectuados para el diagnóstico lesional y en el seguimiento, y la evolución de los pacientes junto al éxito o el fracaso del método. Resultados: Se trataron 22 lesiones esplénicas, 27 renales y 16 hepáticas. Para el diagnóstico y el seguimiento se efectuaron ecografía y TAC en forma combinada o como único método. Los criterios de inclusión fueron la existencia de estabilidad de la normalidad hemodinámica y la ausencia de lesiones asociadas con requerimiento de cirugía. La evolución de los pacientes fue satisfactoria en 17 (77,27 por ciento) lesiones esplénicas, 14 (87,5 por ciento) hepáticas y en 25 (92,59 por ciento) renales. Conclusiones: El tratamiento no operatorio es una terapéutica válida para muchas lesiones esplénicas, hepáticas y renales. Para su implementación debe existir estabilidad de la normalidad hemodinámica y ausencia de lesiones asociadas de tratamiento quirúrgico. El seguimiento debe estar basado principalmente en la evolución clínica de los pacientes

Lesiones traumáticas contusas del abdómen: tratamiento no operatorio / Blunt abdominal trauma: nonoperative management

Antecedentes: Históricamente, las lesiones traumáticas del abdomen fueron tratados en forma quirúrgica. Pero desde un tiempo existe una tendencia creciente hacia el manejo no operatorio de estas lesiones, fundamentalmente en las correspondencias a los traumatismos por contusión. Objetivo: Analizar una serie de casos de lesiones traumáticas contusas del abdómen, a las que se les efectuó tratamiento no operatorio, para evaluar la efectividad del método. Lugar y aplicación: Servicios de Emergencias y de Cirugía General. Diseño: Estudio observacional retrospectivo basado en criterios básicos y descripción de hallazgos clínicos. Población: Muestra consecutiva de 60 casos de pacientes asistidos por presentar 65 lesiones traumáticas contusas del abdómen, tratados en forma no operatoria entre el 1/1/95 y el 15/11/04. Método: Se analizaron las historias clínicas de los pacientes de la población en estudio para determinar las diferentes lesiones tratadas; los criterios de inclusión utilizados, los métodos de estudio efectuados para el diagnóstico lesional y en el seguimiento, y la evolución de los pacientes junto al éxito o el fracaso del método. Resultados: Se trataron 22 lesiones esplénicas, 27 renales y 16 hepáticas. Para el diagnóstico y el seguimiento se efectuaron ecografía y TAC en forma combinada o como único método. Los criterios de inclusión fueron la existencia de estabilidad de la normalidad hemodinámica y la ausencia de lesiones asociadas con requerimiento de cirugía. La evolución de los pacientes fue satisfactoria en 17 (77,27 por ciento) lesiones esplénicas, 14 (87,5 por ciento) hepáticas y en 25 (92,59 por ciento) renales. Conclusiones: El tratamiento no operatorio es una terapéutica válida para muchas lesiones esplénicas, hepáticas y renales. Para su implementación debe existir estabilidad de la normalidad hemodinámica y ausencia de lesiones asociadas de tratamiento quirúrgico. El seguimiento debe estar basado principalmente en la evolución clínica de los pacientes (AU)

Un resbalón diagnóstico: luxación rotuliana traumática no sospechada. Signos directos e indirectos observados por resonancia magnética / A diagnostic pitfall: unsuspected patellar traumatic luxation. MRI direct and indirect signs

Propósito: Nos llamó la atención la frecuencia de luxaciones rotulianas traumáticas (LRT) no sospechadas durante la consulta y el examen físico de pacientes que exploramos por gonalgia o inestabilidad mediante resonancia magnética (RM). Nuestro Objetivo es demostrar los signos de LRT que hallamos en estos pacientes y las estructuras anatómicas que resultan más frecuentemente afectadas. Material y método: Diez y ocho pacientes con LRT fueron explorados mediante RM con cortes axiales, coronales y sagitales ponderados en T1 y T2. Resultados: El 61,1 por ciento de los pacientes no presentaba sospecha de LRT antes del examen y relataba un episodio de esguince o traumatismo como comienzo de los síntomas; el 83,3 por ciento mostró lesión del retináculo interno y el ligamento femoropatelar (LFP). Las contusiones óseas en la cara medial de la rótula estuvieron presentes en el 88,8 por ciento y en el borde lateral del cóndilo femoral externo en el 100 por ciento. El 1,1 por ciento mostró un fragmento óseo patelar desprendido y el 55,5 por ciento mostró lateral del cóndilo femoral externo en el 100 por ciento. El 1,1 por ciento mostró un fragmento óseo patelar desprendido y el 55,5 por ciento mostró lateral del cóndilo femoral externo en el 100 por ciento. El 1,1 por ciento mostró un fragmento óseo patelar desprendido y el 55,5 por ciento mostró condromalacia traumática. Todos presentaron derrame articular. "Patela alta" se comprobó en el 55,5 por ciento de los casos. La rótula subluxada estuvo presente en el 72,2 por ciento. Conclusión: La LRT pasa muchas veces desapercibida en la consulta traumatológica. La RM constituye en un método eficáz para su diagnóstico, siempre y cuando se interpreten correctamente los signos de presentación de esta patología. El diagnóstico correcto de una lesión no sospechada puede provocar un cambio en la terapéutica y el manejo del paciente

Un resbalón diagnóstico: luxación rotuliana traumática no sospechada. Signos directos e indirectos observados por resonancia magnética / A diagnostic pitfall: unsuspected patellar traumatic luxation. MRI direct and indirect signs

Propósito: Nos llamó la atención la frecuencia de luxaciones rotulianas traumáticas (LRT) no sospechadas durante la consulta y el examen físico de pacientes que exploramos por gonalgia o inestabilidad mediante resonancia magnética (RM). Nuestro Objetivo es demostrar los signos de LRT que hallamos en estos pacientes y las estructuras anatómicas que resultan más frecuentemente afectadas. Material y método: Diez y ocho pacientes con LRT fueron explorados mediante RM con cortes axiales, coronales y sagitales ponderados en T1 y T2. Resultados: El 61,1 por ciento de los pacientes no presentaba sospecha de LRT antes del examen y relataba un episodio de esguince o traumatismo como comienzo de los síntomas; el 83,3 por ciento mostró lesión del retináculo interno y el ligamento femoropatelar (LFP). Las contusiones óseas en la cara medial de la rótula estuvieron presentes en el 88,8 por ciento y en el borde lateral del cóndilo femoral externo en el 100 por ciento. El 1,1 por ciento mostró un fragmento óseo patelar desprendido y el 55,5 por ciento mostró lateral del cóndilo femoral externo en el 100 por ciento. El 1,1 por ciento mostró un fragmento óseo patelar desprendido y el 55,5 por ciento mostró lateral del cóndilo femoral externo en el 100 por ciento. El 1,1 por ciento mostró un fragmento óseo patelar desprendido y el 55,5 por ciento mostró condromalacia traumática. Todos presentaron derrame articular. "Patela alta" se comprobó en el 55,5 por ciento de los casos. La rótula subluxada estuvo presente en el 72,2 por ciento. Conclusión: La LRT pasa muchas veces desapercibida en la consulta traumatológica. La RM constituye en un método eficáz para su diagnóstico, siempre y cuando se interpreten correctamente los signos de presentación de esta patología. El diagnóstico correcto de una lesión no sospechada puede provocar un cambio en la terapéutica y el manejo del paciente (AU)

Policosanol, reaction time and event-related potentials.

The aim of the present study was to compare the results of a 1-week, double-blind placebo-controlled trial investigating the effects of isopolicosanol and octacosanol on reactivity and related brain activity. In particular, reaction time (RT) and event-related potentials such as contingent negative variations (CNV) and P300 (P3) have been studied. Thirty sedentary healthy students were tested before and after treatment (3.6 mg/die for 7 days) with orally administered tablets of placebo (group A), isopolicosanol (B) and octacosanol (C). RT were studied according to three procedures: simple RT (SRT), go/no-go RT (GRT) and choice RT (CRT). Results show that before treatment, there were no significant differences between groups A, B and C. After treatment, the RT of group A was unchanged, while the RT of groups B and C were reduced. In group B, in the SRT test, the reduction of RT was accompanied by electrical data exhibiting increased amplitudes of CNV and shorter latencies of P3. These results show that the main effect on reactivity and event-related potentials can be ascribed to policosanol and is mainly evident in the SRT test.

Reactivity and event-related potentials during attentional tests in athletes.

A series of attentional tests involving reaction times (RTs) was administered to 12 high-level young (age 17-18 years) volleyball players. During the tests, event-related potentials were recorded by electroencephalogram. In a simple reaction-time test (SRT), the subjects had to respond to a letter that appeared on a white screen. Other tests (attentional shifting tests) consisted of a go/no-go reaction time and a choice reaction time (CRT), divided into a short-latency CRT and a long-latency CRT. In the pre-stimulus period of these tests, there is a shift from broad attention to selective attention, represented by a crowding of black points on the computer screen, followed by the appearance of a letter in the centre of the crowding. The results show that RT increased from SRT to CRT. In the attentional shifting tests, averaged waves of event-related potentials showed a contingent-negative-variation-like wave that was closely related to selective attention (selective attention wave, SAW) before the onset of the stimulus. After the stimulus, a P3 complex was recorded. Correlations were found between the SAW amplitude and P3 latency and amplitude, and between these parameters and RT and its variability. Higher SAW and P3 amplitudes were accompanied by a shorter RT and a lower variability. The characteristics and the correlations that exist between the various parameters are consistent with a possible use of these tests in the analysis of the attentional styles of athletes, and in the evaluation of their progress with training.

Emotional behavior in female rabbits: hippocampal EEG and neuroendocrine aspects.

Behavior, hippocampal electrical activity, plasma hormones and hippocampal choline acetyltransferase (ChAT) were considered in two groups of female rabbits, different in age and condition of breeding, both in the presence and absence of emotional stimuli. In the two groups of female rabbits (4 and 18 months old), permanent electrodes were implanted bilaterally in the two dorsal hippocampi and, one week later, the animals were exposed for three consecutive days to the following tests: Day 1, novel environment (NE); Day 2, object with odor (O); Day 3, sparrow hawk (SP). Behavior: in comparison with Day 1, exploration was decreased by the object and by the sparrow hawk in the older females and increased in the younger ones. Quiet and alert immobility was higher during the SP test, while freezing and pointing were lower in the older females than in the young ones. Electrical activity: peak frequency was lower in younger females than in the older ones. The frequency band distribution corresponding to exploration and immobility showed that in the older females the % of high frequency band increased from the first to the third day of testing, while an opposite trend was present in the younger females. In the case of freezing the hippocampal electric activity showed a more rhythmical component in younger females than in the older ones. Hormones: increased corticosterone levels after the SP test were directly correlated with exploration and inversely correlated with freezing. Dorsal hippocampal ChAT was directly correlated with quiet immobility. These data indicate a relationship between the responses to the anxious/fearful stimuli and the age and/or breeding experience of the female rabbits; this is shown by both the hippocampal electrical activity and the behavioral differences between the two groups.

Hippocampal electrical activity in rabbits during exploration of a semi-natural environment.

The hippocampal EEG shows characteristic profiles during different behavioural items. A class of hippocampal neurones is active when the animal is in specific places of an environment (place units). However, there are only a few neurones and the role of the hippocampal EEG in spatial information processing remains to be explained. In the present experiment we studied the exploratory behaviour of rabbits (implanted with chronic electrodes in the hippocampus) in an open-air, semi-natural environment. Hippocampal EEG was recorded by telemetry and related to exploratory behaviour by superimposition onto video. Six rabbits were introduced singly to the semi-natural environment and each remained there for 3 days. Their behaviour and EEG was analysed for three 30 min sessions (at 0, 6 and 56 h). Exploration was the main behaviour in the first observation and decreased progressively in the following sessions. The environment was divided into three zones which were explored differently through time. The hippocampal EEG, recorded during exploration, presented an increase of frequency from the first to the second observation. However, since EEG frequency increased when the animal explored the central area of the enclosure, a response in the place domain cannot be excluded.